xmlwf in libexpat before 2.8.2 has an integer overflow in endDoctypeDecl via NOTATION declarations.
Key facts
- Attack vector
- Local
- Privileges required
- None
- User interaction
- None
- Attack complexity
- High
- Impact type
- Code execution
- Confidentiality · integrity · availability
- High · High · Low
- Fix status
- Partial Red Hat: 1 fixed, 3 without a fix
Attack profile from CVSS 3.1 · CNA. Fix status from CNA and Red Hat. Impact type from CWE-190 and the CVSS impact.
Summary
xmlwf in libexpat before 2.8.2 has an integer overflow in endDoctypeDecl via NOTATION declarations.
Why it matters now
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 2.8.2 | 2.8.2 | Patch available | CNA |
- libexpat Vendorlibexpat project Affected before 2.8.2 Fixed in 2.8.2 Patch available CNA
CPE configurations NVD · 1
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:libexpat_project:libexpat:*:*:*:*:*:*:*:* | before 2.8.2 | Vulnerable | libexpat project |
- cpe:2.3:a:libexpat_project:libexpat:*:*:*:*:*:*:*:* Versions before 2.8.2 Vulnerable ·libexpat project
Remediation
- Fix · CNA libexpat (libexpat project) Fixed in 2.8.2
Red Hat 1 advisory
- RHSA-2026:65568 Released 2026-09-08 · Red Hat rating ImportantRed Hat Hardened Images RPMs Security Update
- Red Hat Hardened Images expat-2.8.4-0.1.hum1@aarch64, expat-2.8.4-0.1.hum1@src, expat-2.8.4-0.1.hum1@x86_64 +4
Fixed in the same release
Records fixed by the same vendor advisory or release, as the CNA lists them.
- Release ·
libexpat 2.8.2
10 records Highest priority Priority LOW 10 LOW
Other records, highest priority first
- TI-2026-40765 libexpat before 2.8.2 has an integer overflow in doProlog that is related to storeEntityValue and entity textLen.Priority LOW 32
- TI-2026-40764 Integer overflow in libexpatPriority LOW 32
- TI-2026-40761 libexpat before 2.8.2 has an integer overflow in storeAtts.Priority LOW 32
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Exploit Intelligence | Affected | No fix yet: Fix deferred |
| Red Hat Ansible Automation Platform 2 | Affected | No fix yet: Fix deferred |
| Red Hat OpenShift AI (RHOAI) | Affected | No fix yet: Fix deferred |
| Red Hat Hardened Images | Fixed | RHSA-2026:65568 |
Timeline
- 2026-10-02 Threatist record created from CVE-2026-56411
- 2026-10-03 Alias added: GHSA-68vw-xv3c-52vp
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-2026-56411 · CVE Program
- CVE-2026-56411 · NVD
- FIRST EPSS
- GHSA-68vw-xv3c-52vp · GitHub Advisory Database · CC BY 4.0
- CVE-2026-56411 · Red Hat security data · CC BY 4.0
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