CVE-2026-45186
📛 CVE Title
CVE-2026-45186
Description
In libexpat before 2.8.1, the computational complexity of attribute name collision checks allows a denial of service via moderately sized crafted XML input.
Overview
- State
- PUBLISHED
- Assigner (CNA)
- mitre
- CVSS severity
- LOW
- CVSS score
- 2.9 / 10
- CVSS vector
CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L- Effective score
- 2.9 / 10 LOW source: CNA overview
- MSRC score
- 2.9 / 10 LOW MS rating: Low
- CWE(s)
-
CWE-407 - Reserved
- 2026-05-10
- Published
- 2026-05-10 08:36 UTC
- Last updated
- 2026-05-12 00:23 UTC
- Source
- https://raw.githubusercontent.com/CVEProject/cvelistV5/main/cves/2026/45xxx/CVE-2026-45186.json
- Linked Threat
- CVE-2026-45186 — CVE-2026-45186
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
- 2026-05-10 07:16:07 UTC
- NVD last modified
- 2026-05-14 17:20:32 UTC
- NVD CVSS v3.1
- 2.9 / 10 LOW source: cve@mitre.org
- NVD CVSS vector
CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L- Exploitability subscore
- 1.4 / 10
- Impact subscore
- 1.4 / 10
- EPSS score
- 0.0001 (probability of exploitation in next 30 days)
- EPSS percentile
- 1.47% vs all CVEs — higher = more likely to be exploited, as of 2026-05-24
NVD / KEV / EPSS data refreshed 2026-05-25 08:31 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-2026-28985 - Assigner
- mitre
- Published
- May 10, 2026, 6:36:16 AM
- Updated
- May 11, 2026, 10:23:27 PM
- EUVD base score (CVSS 3.1)
-
2.9 / 10
CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L - EUVD-reported EPSS
- 0.0100
- Vendors
- libexpat project
- Products
-
libexpat (0 <2.8.1)
ENISA description: In libexpat before 2.8.1, the computational complexity of attribute name collision checks allows a denial of service via moderately sized crafted XML input.
EUVD references (1)
Microsoft Security Response Center MSRC
Microsoft's vendor-authoritative record from the Security Update Guide — its own CVSS score, impact, severity rating, exploit assessment, and KB-article fixes. Refreshed 2026-07-28 03:00 UTC (source: CVRF).
- MS severity
- Low
- MS CVSS base score
- 2.9 / 10 (temporal 2.9)
CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L - Release
- 2026-May
Microsoft remediations / KB articles (2)
- CBL-Mariner Releases — Vendor Fix / Security Update (fixed build 2.8.2-1)
- https://learn.microsoft.com/en-us/azure/azure-linux/tutorial-azure-linux-upgrade — None Available / CBL-Mariner Releases
Affected products (1)
| Vendor | Product | Versions | Platforms |
|---|---|---|---|
| libexpat project | libexpat |
0 (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:libexpat_project:libexpat:*:*:*:*:*:*:*:*
Vendor references (1)
References embedded in the original CVE record by the assigning CNA.
MITRE references (1) cveawg.mitre.org
Pulled from MITRE's CVE Services API by the 🛰 Backfill from MITRE button.
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.
- None Available msrc
- MSRC update guide: CVE-2026-45186 msrc
- https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-28985 rapid7:euvd.enisa.europa.eu
- http://cwe.mitre.org/data/definitions/407.html rapid7:cwe.mitre.org
- https://attackerkb.com/topics/CVE-2026-45186 rapid7:attackerkb.com
- https://nvd.nist.gov/vuln/detail/CVE-2026-45186 tenable:nvd.nist.gov
- https://www.cve.org/CVERecord?id=CVE-2026-45186 tenable:www.cve.org
- https://www.first.org/epss/ tenable:www.first.org
- http://www.openwall.com/lists/oss-security/2026/05/11/16 tenable:www.openwall.com
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.
- http://www.openwall.com/lists/oss-security/2026/05/11/16 af854a3a-2127-422b-91ae-364da2661108 Mailing ListThird Party Advisory
- https://github.com/libexpat/libexpat/pull/1216 cve@mitre.org ExploitIssue TrackingPatch
Remediations (18)
Remediations are stored against the linked Threat row; the list below is deduplicated across both pages.
-
web:blog.qualys.com
With Qualys Policy Audit's out-of-the-box mitigation or Compensatory Controls, which reduce the risk of a vulnerability being exploited because the remediation ( fix / patch ) cannot be done immediately, these security controls are not recommended by any industry standards, such as CIS and DISA-STIG.
2026-05-23 21:03 UTC -
web:blog.talosintelligence.com
Microsoft Patch Tuesday for October 2025 — Snort rules and prominent vulnerabilities Microsoft has released its monthly security update for October 2025, addressing 175 Microsoft CVEs and 21 non-Microsoft CVEs . Among these, 17 vulnerabilities are considered critical and 11 are flagged as important and considered more likely to be exploited.
2026-05-23 21:03 UTC -
web:cisa.gov
Update (08/12/2025): CISA has updated this alert to provide clarification on identifying Exchange Servers on an organization's networks and provided further guidance on running the Microsoft Exchange Health Checker. Update (08/07/2025): CISA issued Emergency Directive (ED) 25-02: Mitigate Microsoft Exchange Vulnerability in response to CVE -2025-53786
2026-05-23 21:03 UTC -
web:cyberpress.org
The U.S. Cybersecurity and Infrastructure Security Agency (CISA) has added two actively exploited Microsoft Defender vulnerabilities to its Known Exploited Vulnerabilities (KEV) catalog, issuing an urgent remediation directive for federal agencies with a due date of June 3, 2026 .
2026-05-23 21:03 UTC -
web:krebsonsecurity.com
The reason is that after the Patch Tuesday on October 14, 2025, Microsoft will stop shipping free security updates for Windows 10 computers.
2026-05-23 21:03 UTC -
web:nvd.nist.gov
An official website of the United States government Here's how you know
2026-05-23 21:03 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 21:03 UTC -
web:vulert.com
Microsoft's May 2026 Patch Tuesday fixes 138 vulnerabilities, including critical Windows DNS and Netlogon RCE flaws. Learn the risks, key CVEs , mitigation steps, and how Vulert can help.
2026-05-23 21:03 UTC -
web:www.crowdstrike.com
Microsoft has released security updates for 107 vulnerabilities, including one publicly disclosed zero-day and 13 critical, in its August 2025 Patch Tuesday rollout.
2026-05-23 21:03 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 21:03 UTC -
web:blogs.oracle.com
For more information about the Critical Patch Update program, see the security vulnerability remediation practices page located on the Oracle Trust Center.
2026-05-26 02:51 UTC -
web:msrc.microsoft.com
Security Update Guide - Microsoft Security Response Center
2026-05-26 02:51 UTC -
web:support.servicenow.com
Overview The advisories below document publicly disclosed Common Vulnerabilities and Exposures ( CVEs ) in the Now Platform by ServiceNow. Because ServiceNow uses various methods to communicate vulnerability information, patches, and other fixes, customers should review family, security patch , and hotfix release notes, which are available at https://docs.servicenow.com, for a complete list of ...
2026-05-26 02:51 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.
2026-05-26 02:51 UTC -
web:www.forbes.com
Updated May 17: This article, originally published May 16, has been updated to include further details on the emergency mitigation process recommended after the CVE - 2026 -42897 Microsoft Exchange ...
2026-05-26 02:51 UTC -
web:www.microsoft.com
These Knowledge Base articles accompany all security updates and advisories, and include caveats or known issues with security updates. Additionally, support engineers document common concerns from customers in these KB articles. These Knowledge Base articles are published the Security Update Guide with each release on Patch Tuesday.
2026-05-26 02:51 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 02:51 UTC -
web:www.techradar.com
Microsoft patches two actively exploited zero‑day flaws in Defender, tracked as CVE‑2026‑41091 (privilege escalation) and CVE‑2026‑45498 (denial of service) Updates were shipped ...
2026-05-26 02:51 UTC
AI Forensic Analysis
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Raw JSON
The full cvelistV5 record. Download as CVE-2026-45186.json.
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