CVE-2026-46356
📛 CVE Title
Fleet: IP spoofing allows bypassing API rate limiting
Description
Fleet is open source device management software. Prior to version 4.80.1, a vulnerability in Fleet's IP extraction logic allows unauthenticated attackers to bypass API rate limiting by spoofing client IP headers. This may allow brute-force login attempts or other abuse against Fleet instances exposed to the public internet. Fleet extracted client IP addresses from request headers (`True-Client-IP`, `X-Real-IP`, `X-Forwarded-For`) without validating that those headers originate from a trusted proxy. The extracted IP is used as the key for rate limiting and IP ban decisions. As a result, an attacker could rotate the value of these headers on each request, causing Fleet to treat each attempt as coming from a different client. This effectively bypasses per-IP rate limits on sensitive endpoints such as the login API, enabling unrestricted brute-force or credential stuffing attacks. This issue primarily affects Fleet instances that are directly exposed to the internet without a reverse proxy that overwrites forwarded-IP headers. Instances behind a properly configured proxy or WAF are less affected. Version 4.80.1 contains a patch. If an immediate upgrade is not possible, administrators should ensure Fleet is deployed behind a reverse proxy (e.g., nginx, Cloudflare, AWS ALB) that overwrites `X-Forwarded-For` with the true client IP, and apply rate limiting at the proxy or WAF layer.
Overview
- State
- PUBLISHED
- Assigner (CNA)
- GitHub_M
- CVSS severity
- MEDIUM
- CVSS score
- 6.9 / 10
- CVSS vector
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N- Effective score
- 6.9 / 10 MEDIUM source: CNA overview
- CWE(s)
-
CWE-290 - Reserved
- 2026-05-13
- Published
- 2026-05-14 21:03 UTC
- Last updated
- 2026-05-14 21:39 UTC
- Source
- https://raw.githubusercontent.com/CVEProject/cvelistV5/main/cves/2026/46xxx/CVE-2026-46356.json
- Linked Threat
- CVE-2026-46356 — CVE-2026-46356
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
- 2026-05-14 20:17:09 UTC
- NVD last modified
- 2026-05-18 15:27:53 UTC
- NVD CVSS v3.1
- 7.5 / 10 HIGH source: nvd@nist.gov
- NVD CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N- Exploitability subscore
- 3.9 / 10
- Impact subscore
- 3.6 / 10
- EPSS score
- 0.0008 (probability of exploitation in next 30 days)
- EPSS percentile
- 24.10% vs all CVEs — higher = more likely to be exploited, as of 2026-05-24
NVD / KEV / EPSS data refreshed 2026-05-25 08:27 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-2026-30416 - Assigner
- GitHub_M
- Published
- May 14, 2026, 7:03:50 PM
- Updated
- May 14, 2026, 7:39:08 PM
- EUVD base score (CVSS 4.0)
-
6.9 / 10
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N - EUVD-reported EPSS
- 0.0800
- Vendors
- fleetdm
- Products
-
Fleet (< 4.80.1)Fleet (< 4.80.1)
- Aliases
-
GHSA-mxmp-wr3w-rvqx
ENISA description: Fleet is open source device management software. Prior to version 4.80.1, a vulnerability in Fleet's IP extraction logic allows unauthenticated attackers to bypass API rate limiting by spoofing client IP headers. This may allow brute-force login attempts or other abuse against Fleet instances exposed to the public internet. Fleet extracted client IP addresses from request headers (`True-Client-IP`, `X-Real-IP`, `X-Forwarded-For`) without validating that those headers originate from a trusted proxy. The extracted IP is used as the key for rate limiting and IP ban decisions. As a result, an attacker could rotate the value of these headers on each request, causing Fleet to treat each attempt as coming from a different client. This effectively bypasses per-IP rate limits on sensitive endpoints such as the login API, enabling unrestricted brute-force or credential stuffing attacks. This issue primarily affects Fleet instances that are directly exposed to the internet without a reverse proxy that overwrites forwarded-IP headers. Instances behind a properly configured proxy or WAF are less affected. Version 4.80.1 contains a patch. If an immediate upgrade is not possible, administrators should ensure Fleet is deployed behind a reverse proxy (e.g., nginx, Cloudflare, AWS ALB) that overwrites `X-Forwarded-For` with the true client IP, and apply rate limiting at the proxy or WAF layer.
Affected products (1)
| Vendor | Product | Versions | Platforms |
|---|---|---|---|
| fleetdm | fleet |
< 4.80.1 (affected)
|
— |
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:a:fleetdm:fleet:*:*:*:*:*:*:*:*
Vendor references (2)
References embedded in the original CVE record by the assigning CNA.
- https://github.com/fleetdm/fleet/security/advisories/GHSA-mxmp-wr3w-rvqx x_refsource_CONFIRM
- https://github.com/fleetdm/fleet/releases/tag/fleet-v4.80.1 x_refsource_MISC
MITRE references (2) cveawg.mitre.org
Pulled from MITRE's CVE Services API by the 🛰 Backfill from MITRE button.
- https://github.com/fleetdm/fleet/releases/tag/fleet-v4.80.1 x_refsource_MISC
- https://github.com/fleetdm/fleet/security/advisories/GHSA-mxmp-wr3w-rvqx x_refsource_CONFIRM
Web references (3)
DuckDuckGo results ranked by threat-intel / vendor advisory domains. Generated by the 🔎 Find references (web) button above — same flow as the Remediations search.
- https://nvd.nist.gov/vuln/detail/CVE-2026-46356 tenable:nvd.nist.gov
- https://www.cve.org/CVERecord?id=CVE-2026-46356 tenable:www.cve.org
- https://www.first.org/epss/ tenable:www.first.org
NVD-tagged references (2)
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://github.com/fleetdm/fleet/releases/tag/fleet-v4.80.1 security-advisories@github.com Release Notes
- https://github.com/fleetdm/fleet/security/advisories/GHSA-mxmp-wr3w-rvqx security-advisories@github.com Vendor Advisory
Remediations (18)
Remediations are stored against the linked Threat row; the list below is deduplicated across both pages.
-
web:docs.oracle.com
Oracle Critical Patch Update (CPU) April 2026 for Oracle Java SE Services: Java Management Release Date: April 21, 2026
2026-05-23 20:53 UTC -
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.
2026-05-23 20:53 UTC -
web:layerlogix.com
April 2026 Patch Tuesday drops today. Here's what's critical, what to patch first, and how Houston IT teams should handle deployment — including the Secure Boot certificate deadline reminder.
2026-05-23 20:53 UTC -
web:nvd.nist.gov
An official website of the United States government Here's how you know
2026-05-23 20:53 UTC -
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.
2026-05-23 20:53 UTC -
web:www.crowdstrike.com
Microsoft's April 2026 Patch Tuesday addresses 164 CVEs , featuring 8 Critical vulnerabilities, one exploited zero-day, and one disclosed zero-day.
2026-05-23 20:53 UTC -
web:www.linkedin.com
Oracle has released its January 2026 Critical Patch Update (CPU), a wide-ranging security bulletin that addresses 337 newly identified vulnerabilities across a broad spectrum of its enterprise ...
2026-05-23 20:53 UTC -
web:www.securityweek.com
Oracle on Tuesday announced the release of 481 new security patches as part of its April 2026 Critical Patch Update (CPU). Across the 28 product families that received security updates, more than 300 patches address vulnerabilities that are remotely exploitable without authentication.
2026-05-23 20:53 UTC -
web:www.windowslatest.com
Windows 11 April 2026 update adds Narrator Copilot support, faster Settings, File Explorer fixes, and key security improvements.
2026-05-23 20:53 UTC -
web:zecurit.com
Get the complete breakdown of Microsoft's May 2026 Patch Tuesday. We analyze the latest security updates and all critical CVEs .
2026-05-23 20:53 UTC -
web:bophin.com
The Ticking Clock of Cybersecurity: Why the Fortinet EMS Flaw Demands Urgent Attention The recent directive from the U.S. Cybersecurity and Infrastructure Security Agency (CISA) ordering federal agencies to patch a critical Fortinet EMS vulnerability by Friday is more than just another cybersecurity alert—it's a stark reminder of the fragility of our digital infrastructure. But what makes ...
2026-05-26 02:57 UTC -
web:msrc.microsoft.com
The Microsoft Security Response Center (MSRC) investigates all reports of security vulnerabilities affecting Microsoft products and services, and provides the information here as part of the ongoing effort to help you manage security risks and help keep your systems protected.
2026-05-26 02:57 UTC -
web:nvd.nist.gov
An official website of the United States government Here's how you know
2026-05-26 02:57 UTC -
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 ...
2026-05-26 02:57 UTC -
web:www.crowdstrike.com
Microsoft has released security updates for 130 vulnerabilities, including 30 critical, in its May 2026 Patch Tuesday rollout.
2026-05-26 02:57 UTC -
web:www.helpnetsecurity.com
Microsoft has marked May 2026 Patch Tuesday by releasing fixes for 120+ CVE -numbered vulnerabilities, none of which are actively exploited.
2026-05-26 02:57 UTC -
web:www.oracle.com
This Critical Patch Update contains 481 new security patches across the product families listed below. Please note that an MOS note summarizing the content of this Critical Patch Update and other Oracle Software Security Assurance activities is located at April 2026 Critical Patch Update: Executive Summary and Analysis.
2026-05-26 02:57 UTC -
web:www.recastsoftware.com
This April was the most active month observed so far in terms of third‑party vulnerability disclosures and remediation activity. During the month, 360 unique vulnerabilities were identified across 96 applications, with vendors releasing 172 patched versions to address these issues. Compared to earlier months, April represents a clear peak in both vulnerability volume and patch output ...
2026-05-26 02:57 UTC
AI Forensic Analysis
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Raw JSON
The full cvelistV5 record. Download as CVE-2026-46356.json.
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