CVE-2026-56407

Vendorlibexpat projectProductlibexpatDiscoveredJun 21, 2026UpdatedOct 25, 2026

libexpat before 2.8.2 has an integer overflow in doProlog that is related to storeEntityValue and entity textLen.

CVSS v3.1

6.9 MEDIUM

EPSS

0.17%

probability of exploitation in 30 days

CISA KEV

Not listed

no confirmed exploitation reported

News coverage

sources referencing this CVE

Related IOCs

seen in the same coverage

Intelligence Reports1

1 intelligence report available

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EPSS Trend

Aug 26, 2026 → Sep 28, 2026

▲ 0.04pp

0.14% → 0.17% over 2 tracked changes

CVSS v3.1 Detail

Attack VectorLOCAL

Attack ComplexityHIGH

Privileges RequiredNONE

User InteractionNONE

ScopeUNCHANGED

ConfidentialityHIGH

IntegrityHIGH

AvailabilityLOW

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

Connections

3 relationships

Timeline

disclosure → media coverage

Jun 21, 2026

Disclosure — published as a CVE record. · last revised by NVD Oct 25, 2026

Sep 24, 2026

ubuntu.com reports: USN-8813-1: Expat vulnerabilities