Integer overflow in libexpat
Priority LOW 35CWE-190Published · Updated
Key facts
- Attack vector
- Local
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Code execution
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- Fixed
Attack profile from CVSS 3.1 · NVD. Fix status from CNA. Impact type from CWE-190 and the CVSS impact.
Summary
In libexpat before 2.7.4, the doContent function does not properly determine the buffer size bufSize because there is no integer overflow check for tag buffer reallocation.
Why it matters now
Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00211 11th percentileScored 2026-11-07
Fix Fixed libexpat (libexpat project): 2.7.4
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Total
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| libexpat project | libexpat | before 2.7.4 | 2.7.4 | Patch available | CNA |
- libexpat Vendorlibexpat project Affected before 2.7.4 Fixed in 2.7.4 Patch available CNA
CPE configurations NVD · 1
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:libexpat_project:libexpat:*:*:*:*:*:*:*:* | before 2.7.4 | Vulnerable | libexpat project |
- cpe:2.3:a:libexpat_project:libexpat:*:*:*:*:*:*:*:* Versions before 2.7.4 Vulnerable ·libexpat project
Remediation
- Fix · CNA libexpat (libexpat project) Fixed in 2.7.4
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
Not affected: 5 products
- Red Hat Enterprise Linux 10
- Red Hat Enterprise Linux 6
- Red Hat Enterprise Linux 7
- Red Hat Enterprise Linux 8
- Red Hat Enterprise Linux 9
Timeline
- 2026-10-02 Threatist record created from CVE-2026-25210
- 2026-10-03 Alias added: GHSA-857q-6v86-xp84
References
More libexpat project Libexpat vulnerabilities
- TI-2022-09008 In Expat (aka libexpat) before 2.4.5, there is an integer overflow in storeRawNames. CVSS 3.1CRITICAL 9.8
- TI-2026-79488 Billion laughs detection delay in libexpat enables denial of service CVSS 4.0HIGH 8.7
- TI-2022-08947 xmlparse.c in Expat (aka libexpat) before 2.4.5 allows attackers to insert… CVSS 3.1CRITICAL 9.8
- TI-2021-20962 In Expat (aka libexpat) before 2.4.3, a left shift by 29 (or more) places in the… CVSS 3.1HIGH 8.8
- TI-2021-21076 In doProlog in xmlparse.c in Expat (aka libexpat) before 2.4.3, an integer overflow exists for m_groupSize. CVSS 3.1HIGH 8.1
- TI-2016-00645 Expat allows context-dependent attackers to cause a denial of service (crash) or possibly… CVSS 3.1CRITICAL 9.8
Sources
- CVE-2026-25210 · CVE Program
- CVE-2026-25210 · NVD
- FIRST EPSS
- GHSA-857q-6v86-xp84 · GitHub Advisory Database · CC BY 4.0
- CVE-2026-25210 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences