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TI-2026-40762 Aliases CVE-2026-56404GHSA-h5j3-rr49-jmm6

libexpat before 2.8.2 has an integer overflow in addBinding.

Priority LOW 31CWE-190Published · Updated

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, 8 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

libexpat before 2.8.2 has an integer overflow in addBinding.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.0013 2nd percentileScored 2026-11-07
Fix Partial libexpat (libexpat project): 2.8.2Red Hat: 1 advisoryRed Hat: 1 fixed, 8 without a fix

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

VendorProductAffected versionsFixed inStatusSource
libexpat projectlibexpatbefore 2.8.22.8.2Patch availableCNA
  • libexpat Vendorlibexpat project Affected before 2.8.2 Fixed in 2.8.2 Patch available CNA

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:libexpat_project:libexpat:*:*:*:*:*:*:*:*before 2.8.2Vulnerablelibexpat 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-2026:40486 Released 2026-07-15 · Red Hat rating Moderate
    Red Hat Hardened Images RPMs bug fix and enhancement update
    • Red Hat Hardened Images expat-2.8.2-1.1.hum1@aarch64, expat-2.8.2-1.1.hum1@src, expat-2.8.2-1.1.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 →

ProductStatusPlan or fix
Red Hat Enterprise Linux 10AffectedNo fix yet: Fix deferred
Red Hat Enterprise Linux 6AffectedNo fix planned: Out of support scope
Red Hat Enterprise Linux 7AffectedNo fix planned: Out of support scope
Red Hat Enterprise Linux 8AffectedNo fix yet: Fix deferred
Red Hat Enterprise Linux 9AffectedNo fix yet: Fix deferred
Red Hat OpenShift AI (RHOAI)Affected—
Red Hat OpenShift Container Platform 4AffectedNo fix yet: Fix deferred
Red Hat OpenShift Container Platform 5AffectedNo fix yet: Fix deferred
Red Hat Hardened ImagesFixed RHSA-2026:40486
Not affected: 1 product
  • Red Hat OpenShift AI (RHOAI)

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-56404
  2. 2026-10-03 Alias added: GHSA-h5j3-rr49-jmm6
  3. 2026-11-06 Affected versions changed · Red Hat
  4. 2026-11-06 Affected versions changed · Red Hat

References

  • 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
See all 67 →

Sources