CVE-2026-45886

CVEs › CVE-2026-45886

Description

In the Linux kernel, the following vulnerability has been resolved: bpf: Fix bpf_xdp_store_bytes proto for read-only arg While making some maps in Cilium read-only from the BPF side, we noticed that the bpf_xdp_store_bytes proto is incorrect. In particular, the verifier was throwing the following error: ; ret = ctx_store_bytes(ctx, l3_off + offsetof(struct iphdr, saddr), &nat->address, 4, 0); 635: (79) r1 = *(u64 *)(r10 -144) ; R1=ctx() R10=fp0 fp-144=ctx() 636: (b4) w2 = 26 ; R2=26 637: (b4) w4 = 4 ; R4=4 638: (b4) w5 = 0 ; R5=0 639: (85) call bpf_xdp_store_bytes#190 write into map forbidden, value_size=6 off=0 size=4 nat comes from a BPF_F_RDONLY_PROG map, so R3 is a PTR_TO_MAP_VALUE. The verifier checks the helper's memory access to R3 in check_mem_size_reg, as it reaches ARG_CONST_SIZE argument. The third argument has expected type ARG_PTR_TO_UNINIT_MEM, which includes the MEM_WRITE flag. The verifier thus checks for a BPF_WRITE access on R3. Given R3 points to a read-only map, the check fails. Conversely, ARG_PTR_TO_UNINIT_MEM can also lead to the helper reading from uninitialized memory. This patch simply fixes the expected argument type to match that of bpf_skb_store_bytes.

Overview

State: PUBLISHED
Assigner (CNA): Linux
CVSS severity: high
CVSS score: 7.1 / 10
CVSS vector: AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H
Effective score: 7.1 / 10 HIGH source: CNA overview
CWE(s): —
Reserved: 2026-05-13
Published: 2026-05-27 12:16 UTC
Last updated: 2026-05-27 12:16 UTC
Source: https://raw.githubusercontent.com/CVEProject/cvelistV5/main/cves/2026/45xxx/CVE-2026-45886.json
Linked Threat: CVE-2026-45886 — CVE-2026-45886

NVD triage scoring NVD CVE 2.0

Layer NVD adds on top of the CNA's CVE record — published / last-modified timestamps, exploitability / impact subscores, and the FIRST.org EPSS probability that this CVE will be exploited in the wild in the next 30 days.

NVD published: 2026-05-27 14:17:02 UTC
NVD last modified: 2026-06-25 21:13:18 UTC
NVD CVSS v3.1: 5.5 / 10 MEDIUM source: nvd@nist.gov
NVD CVSS vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Exploitability subscore: 1.8 / 10
Impact subscore: 3.6 / 10
EPSS score: 0.0016 (probability of exploitation in next 30 days)
EPSS percentile: 5.59% vs all CVEs — higher = more likely to be exploited, as of 2026-07-26

NVD-assigned CWE(s): CWE-908 (differs from the CNA list above)

NVD / KEV / EPSS data refreshed 2026-07-27 12:03 UTC. Re-run the 🛰 Backfill from NVD button above to refresh.

European Union Vulnerability Database ENISA EUVD

ENISA's official EU repository for curated vulnerability intelligence. Carries a separate identifier (EUVD-YYYY-NNNN) and frequently exposes an earlier-published description + CVSS than NVD does.

EUVD ID: EUVD-2026-32352
Assigner: Linux
Published: May 27, 2026, 12:16:58 PM
Updated: May 27, 2026, 12:16:58 PM
EUVD base score: 0.0 / 10
EUVD-reported EPSS: 0.1600
Vendors: Linux
Products: Linux (5.18)

Linux (patch: 6.12.75)

Linux (patch: 7.0)

Linux (patch: 6.6.128)

Linux (3f364222d032eea6b245780e845ad213dab28cdd <ddc34a1b85505c919026ddc82fafdada9a160b15)

Linux (patch: 6.19.4)

Linux (patch: 0)

Linux (3f364222d032eea6b245780e845ad213dab28cdd <6557f1565d779851c4db9c488c49c05a47a6e72f)

Linux (3f364222d032eea6b245780e845ad213dab28cdd <d7b87adeb0eb539b9b824b101bb14fb01e41240b)

Linux (patch: 6.1.165)

Linux (patch: 6.18.14)

Linux (3f364222d032eea6b245780e845ad213dab28cdd <0db169a91381a473b7974021d1c02f8da72c5775)

Linux (3f364222d032eea6b245780e845ad213dab28cdd <ffb5d1c5e3933b947fc7303ad68bf0c536d0c85e)

Linux (3f364222d032eea6b245780e845ad213dab28cdd <57f7f6a0ad04a65c8a7a067b2f56cbbf2aec9e52)
Aliases: GHSA-w77r-v3rv-5rcp

ENISA description: In the Linux kernel, the following vulnerability has been resolved: bpf: Fix bpf_xdp_store_bytes proto for read-only arg While making some maps in Cilium read-only from the BPF side, we noticed that the bpf_xdp_store_bytes proto is incorrect. In particular, the verifier was throwing the following error: ; ret = ctx_store_bytes(ctx, l3_off + offsetof(struct iphdr, saddr), &nat->address, 4, 0); 635: (79) r1 = *(u64 *)(r10 -144) ; R1=ctx() R10=fp0 fp-144=ctx() 636: (b4) w2 = 26 ; R2=26 637: (b4) w4 = 4 ; R4=4 638: (b4) w5 = 0 ; R5=0 639: (85) call bpf_xdp_store_bytes#190 write into map forbidden, value_size=6 off=0 size=4 nat comes from a BPF_F_RDONLY_PROG map, so R3 is a PTR_TO_MAP_VALUE. The verifier checks the helper's memory access to R3 in check_mem_size_reg, as it reaches ARG_CONST_SIZE argument. The third argument has expected type ARG_PTR_TO_UNINIT_MEM, which includes the MEM_WRITE flag. The verifier thus checks for a BPF_WRITE access on R3. Given R3 points to a read-only map, the check fails. Conversely, ARG_PTR_TO_UNINIT_MEM can also lead to the helper reading from uninitialized memory. This patch simply fixes the expected argument type to match that of bpf_skb_store_bytes.

EUVD references (6)

Affected products (2)

Vendor	Product	Versions	Platforms
Linux	Linux	`3f364222d032eea6b245780e845ad213dab28cdd` (affected), `3f364222d032eea6b245780e845ad213dab28cdd` (affected), `3f364222d032eea6b245780e845ad213dab28cdd` (affected), `3f364222d032eea6b245780e845ad213dab28cdd` (affected), `3f364222d032eea6b245780e845ad213dab28cdd` (affected), `3f364222d032eea6b245780e845ad213dab28cdd` (affected)	—
Linux	Linux	`5.18` (affected), `0` (unaffected), `6.1.165` (unaffected), `6.6.128` (unaffected), `6.12.75` (unaffected), `6.18.14` (unaffected), `6.19.4` (unaffected), `7.0` (unaffected)	—

Affected products — CPE 2.3 (1) NVD

NVD's normalized CPE 2.3 matchers, used by vendor tools (vulnerability scanners, asset managers) for automated detection. Compare with the CNA's free-text "Affected products" section above.

cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*

Vendor references (6)

References embedded in the original CVE record by the assigning CNA.

Web references (9)

DuckDuckGo results ranked by threat-intel / vendor advisory domains. Generated by the 🔎 Find references (web) button above — same flow as the Remediations search.

https://git.kernel.org/stable/c/0db169a91381a473b7974021d1c02f8da72c5775 tenable:git.kernel.org
https://git.kernel.org/stable/c/57f7f6a0ad04a65c8a7a067b2f56cbbf2aec9e52 tenable:git.kernel.org
https://git.kernel.org/stable/c/6557f1565d779851c4db9c488c49c05a47a6e72f tenable:git.kernel.org
https://git.kernel.org/stable/c/d7b87adeb0eb539b9b824b101bb14fb01e41240b tenable:git.kernel.org
https://git.kernel.org/stable/c/ddc34a1b85505c919026ddc82fafdada9a160b15 tenable:git.kernel.org
https://git.kernel.org/stable/c/ffb5d1c5e3933b947fc7303ad68bf0c536d0c85e tenable:git.kernel.org
https://nvd.nist.gov/vuln/detail/CVE-2026-45886 tenable:nvd.nist.gov
https://www.cve.org/CVERecord?id=CVE-2026-45886 tenable:www.cve.org
https://www.first.org/epss/ tenable:www.first.org

NVD-tagged references (6)

Reference list NVD curates from the CNA record, vendor advisories, and third-party reports. The tag chips below are NVD's analyst-assigned categories.

https://git.kernel.org/stable/c/0db169a91381a473b7974021d1c02f8da72c5775 416baaa9-dc9f-4396-8d5f-8c081fb06d67 Patch
https://git.kernel.org/stable/c/57f7f6a0ad04a65c8a7a067b2f56cbbf2aec9e52 416baaa9-dc9f-4396-8d5f-8c081fb06d67 Patch
https://git.kernel.org/stable/c/6557f1565d779851c4db9c488c49c05a47a6e72f 416baaa9-dc9f-4396-8d5f-8c081fb06d67 Patch
https://git.kernel.org/stable/c/d7b87adeb0eb539b9b824b101bb14fb01e41240b 416baaa9-dc9f-4396-8d5f-8c081fb06d67 Patch
https://git.kernel.org/stable/c/ddc34a1b85505c919026ddc82fafdada9a160b15 416baaa9-dc9f-4396-8d5f-8c081fb06d67 Patch
https://git.kernel.org/stable/c/ffb5d1c5e3933b947fc7303ad68bf0c536d0c85e 416baaa9-dc9f-4396-8d5f-8c081fb06d67 Patch

Remediations (18)

Remediations are stored against the linked Threat row; the list below is deduplicated across both pages.

CVE-2026-41089 Netlogon RCE: Patch Domain Controllers

web:blog.gridinsoft.com

CVE - 2026 -41089 in Windows Netlogon is now reported as actively exploited. Patch domain controllers and check LSASS, Netlogon, and authentication logs.

2026-06-04 00:16 UTC
Microsoft and Adobe Patch Tuesday, May 2026 Security Update Review

web:blog.qualys.com

May 2026's Patch Tuesday arrives with Microsoft addressing a fresh set of vulnerabilities across its ecosystem, reinforcing the ongoing need for timely patching in an increasingly threat-heavy…

2026-06-04 00:16 UTC
Microsoft Patch Tuesday May 2026 - 120 Vulnerabilities Fixed, Including ...

web:cybersecuritynews.com

Microsoft's May 2026 Patch Tuesday lands with a heavy enterprise focus, fixing 120 vulnerabilities across Windows, Office, Azure, developer tools, and Microsoft 365 apps, including 29 remote code execution (RCE) flaws rated Critical.

2026-06-04 00:16 UTC
Microsoft's May 2026 Patch Tuesday - Hive Pro

web:hivepro.com

Microsoft's May 2026 Patch Tuesday security update addresses 137 critical vulnerabilities across the Microsoft product ecosystem, representing a significant security update for enterprise and consumer environments.

2026-06-04 00:16 UTC
Patch Tuesday, May 2026 Edition - Krebs on Security

web:krebsonsecurity.com

Microsoft expects that exploitation is more likely. May's Patch Tuesday is a welcome respite from April, which saw Microsoft fix a near-record 167 security flaws.

2026-06-04 00:16 UTC
Nvd - Cve-2026-8586

web:nvd.nist.gov

An official website of the United States government Here's how you know

2026-06-04 00:16 UTC
Security Update Guide - Microsoft

web:portal.msrc.microsoft.com

The Security Update Guide provides information on the latest Microsoft security updates, helping users understand and address potential vulnerabilities effectively.

2026-06-04 00:16 UTC
Microsoft May 2026 Patch Tuesday Fixes 120 Flaws

web:thecyberexpress.com

Microsoft has rolled out its May 2026 Patch Tuesday security updates, delivering fixes for approximately 120 vulnerabilities across Windows, Microsoft Office, networking

2026-06-04 00:16 UTC
Microsoft's Patch Tuesday Update Targets 120 Security Flaws

web:www.techrepublic.com

Microsoft's May Patch Tuesday fixes 120 flaws, including 31 remote code execution bugs, with no zero-days reported at release.

2026-06-04 00:16 UTC
Patch Tuesday June 2026: Security Updates & CVE Analysis

web:zecurit.com

Get the complete breakdown of Microsoft's June 2026 Patch Tuesday. We analyze the latest security updates and all critical CVEs .

2026-06-04 00:16 UTC
Microsoft Confirms Defender RoguePlanet 0-Day Exploit and Working to ...

web:cybersecuritynews.com

Microsoft has officially acknowledged a critical zero-day vulnerability in Microsoft Defender, publicly dubbed "RoguePlanet," and confirmed it is actively developing a security patch to address the flaw.

2026-06-19 02:27 UTC
March 13, 2026—Hotpatch KB5084597 (OS Builds 26200.7982 and 26100.7982 ...

web:support.microsoft.com

This update for Windows 11, version 25H2 and 24H2 (KB5084597) incudes security improvements. To learn more about differences between security updates, optional non-security preview updates, out-of-band (OOB) updates, and continuous innovation, see Windows monthly updates explained. For information on Windows update terminology, see the different types of Windows software updates. To view the ...

2026-06-19 02:27 UTC
SAP Security Patch Day - February 2026

web:support.sap.com

SAP security Patch Day Bulletin This post shares the information on security notes that remediate vulnerabilities discovered in SAP products. SAP strongly recommends that the customer visits the Support Portal and applies patches on priority to protect their SAP landscape. On 10th of February 2026 , SAP security patch day saw the release of 26 new security notes. Further, there was 1 update to ...

2026-06-19 02:27 UTC
Critical Patches Issued for Microsoft Products, April 14, 2026

web:www.cisecurity.org

<p>Multiple vulnerabilities have been discovered in Microsoft products, the most severe of which could allow for remote code execution. Successful exploitation of the most severe of these vulnerabilities could result in an attacker gaining the same privileges as the logged-on user. Depending on the privileges associated with the user, an attacker could then install programs; view, change, or ...

2026-06-19 02:27 UTC
May 2026 Patch Tuesday: Updates and Analysis | CrowdStrike

web:www.crowdstrike.com

Microsoft has released security updates for 130 vulnerabilities, including 30 critical, in its May 2026 Patch Tuesday rollout.

2026-06-19 02:27 UTC
Microsoft patches two zero-day flaws in Defender - CSO Online

web:www.csoonline.com

Microsoft released emergency fixes for two zero-day vulnerabilities in the malware protection components of Microsoft Defender. The flaws allow local attackers to gain system-level privileges or ...

2026-06-19 02:27 UTC
Microsoft working on a fix for RoguePlanet, a flaw that grants full PC ...

web:www.malwarebytes.com

Microsoft says it's working on a fix for an unpatched Defender vulnerability that can give attackers the highest level of access on Windows.

2026-06-19 02:27 UTC
Patch Tuesday - June 2026 - Rapid7

web:www.rapid7.com

Microsoft is publishing 200 vulnerabilities on June 2026 Patch Tuesday, including an HTTP/2 denial of service vulnerability and an elevation of privilege vulnerability in PowerToys.

2026-06-19 02:27 UTC

AI Forensic Analysis

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Raw JSON

The full cvelistV5 record. Download as CVE-2026-45886.json.

{
  "containers": {
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          "programFiles": [
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            },
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            },
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              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
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              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.75",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.14",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.19.*",
              "status": "unaffected",
              "version": "6.19.4",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.0",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
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                },
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                },
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              ],
              "negate": false,
              "operator": "OR"
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          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Fix bpf_xdp_store_bytes proto for read-only arg\n\nWhile making some maps in Cilium read-only from the BPF side, we noticed\nthat the bpf_xdp_store_bytes proto is incorrect. In particular, the\nverifier was throwing the following error:\n\n  ; ret = ctx_store_bytes(ctx, l3_off + offsetof(struct iphdr, saddr),\n                          &nat->address, 4, 0);\n  635: (79) r1 = *(u64 *)(r10 -144)     ; R1=ctx() R10=fp0 fp-144=ctx()\n  636: (b4) w2 = 26                     ; R2=26\n  637: (b4) w4 = 4                      ; R4=4\n  638: (b4) w5 = 0                      ; R5=0\n  639: (85) call bpf_xdp_store_bytes#190\n  write into map forbidden, value_size=6 off=0 size=4\n\nnat comes from a BPF_F_RDONLY_PROG map, so R3 is a PTR_TO_MAP_VALUE.\nThe verifier checks the helper's memory access to R3 in\ncheck_mem_size_reg, as it reaches ARG_CONST_SIZE argument. The third\nargument has expected type ARG_PTR_TO_UNINIT_MEM, which includes the\nMEM_WRITE flag. The verifier thus checks for a BPF_WRITE access on R3.\nGiven R3 points to a read-only map, the check fails.\n\nConversely, ARG_PTR_TO_UNINIT_MEM can also lead to the helper reading\nfrom uninitialized memory.\n\nThis patch simply fixes the expected argument type to match that of\nbpf_skb_store_bytes."
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-05-27T12:16:58.000Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
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          "url": "https://git.kernel.org/stable/c/ffb5d1c5e3933b947fc7303ad68bf0c536d0c85e"
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        {
          "url": "https://git.kernel.org/stable/c/ddc34a1b85505c919026ddc82fafdada9a160b15"
        },
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          "url": "https://git.kernel.org/stable/c/0db169a91381a473b7974021d1c02f8da72c5775"
        },
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        },
        {
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        },
        {
          "url": "https://git.kernel.org/stable/c/6557f1565d779851c4db9c488c49c05a47a6e72f"
        }
      ],
      "title": "bpf: Fix bpf_xdp_store_bytes proto for read-only arg",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-45886",
    "datePublished": "2026-05-27T12:16:58.000Z",
    "dateReserved": "2026-05-13T15:03:33.082Z",
    "dateUpdated": "2026-05-27T12:16:58.000Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}