CVE-2026-45186

2.9 LOW 0.5% exploit odds Fix listed Denial of service

What it is

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.

At a glance

Exploitability: Can be exploited locally on the machine without logging in. Limited direct impact.
Exploit odds: 0.5% chance of exploitation in the next 30 days (EPSS).
Fix: A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

2026-05-10 07:16 UTC PublishedDisclosed publicly on CVE.org and NVD
2026-09-16 13:17 UTC Last updatedMost recent change to the record

Why it ranks here

Exploited in the wild: no, CISA does not list it.
Exploit odds: 0.5% in the next 30 days (EPSS).
Severity: 2.9 LOW (CVSS).
Fix: a patch or advisory is linked.

Details

Published: 2026-05-10 07:16 UTC
Last modified: 2026-09-16 13:17 UTC
Exploit probability: 0.5% · EPSS, next 30 days
Weakness: CWE-407
Record status: Modified

Affected

Libexpat Project Libexpat < 2.8.1

Attack profile CVSS 3.1 · 2.9

Attack vector: Local
Complexity: High
Privileges needed: None
User interaction: None
Scope: Unchanged
Confidentiality: None
Integrity: None
Availability: Low

Raw vector

CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L

Is it in your code?

Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.

Read https://cve-list.com/agent/cve/CVE-2026-45186.md and follow it. Check whether this project is affected by CVE-2026-45186. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

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Fix and advisories

https://github.com/libexpat/libexpat/pull/1216

References

NVD record · CVE.org record