← CVE Radar
CVE-2026-118370libexpat through 2.9.0 Integer Overflow in storeAtts via attIndex and nPrefixes
libexpat through 2.9.0 contains a signed integer overflow vulnerability in storeAtts() in lib/xmlparse.c that allows attackers to trigger out-of-bounds writes via oversized attribute counts. Attackers can supply a multi-gigabyte document with a start tag carrying over 2^30 attributes to overflow attIndex and nPrefixes, crashing applications or corrupting heap memory.
8.2 HIGHEPSS 0.39%Not in KEVNVD: Analyzed
Overview
Severity
| Score | Severity | Version | Vector String |
|---|---|---|---|
| 8.2 | HIGH | 4.0VulnCheck (CNA) | CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N |
| 8.2 | HIGH | 3.1NVD | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:H |
| 5.9 | MEDIUM | 3.1VulnCheck (CNA) | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H |
Details
- CVE ID
- CVE-2026-118370
- Status
- Analyzed
- Assigner (CNA)
- VulnCheck
- Published
- Oct 28, 2026
- Last modified
- 2026-11-02 20:17 UTC
- Weaknesses
- CWE-190 · Integer Overflow or Wraparound
Affected Products
As published by the CNA in the CVE record.
libexpatlibexpat1 version range
- through 2.9.0
References
- github.com https://github.com/libexpat/libexpat
- github.com https://github.com/libexpat/libexpat/blob/a76b1174c1ea52abb639a4c69d52b630a8a106a2/expat/lib/xmlparse.c#L4138-L4140
- github.com https://github.com/libexpat/libexpat/commit/1bac53c4fc460a03cd9860f39501c7979f6750ae
- github.com https://github.com/libexpat/libexpat/commit/621cb2c78b253ee023a86bc91d6ddb048481c04c
- github.com https://github.com/libexpat/libexpat/pull/1450
- vulncheck.com https://www.vulncheck.com/advisories/libexpat-through-2.9.0-integer-overflow-in-storeatts-via-attindex-and-nprefixes