Is there a public exploit for CVE-2026-77214?

No public exploit for CVE-2026-77214 was found in Exploit-DB, Metasploit, Nuclei templates or public proof-of-concept repositories. That is an absence of evidence rather than proof that none exists.

How severe is CVE-2026-77214?

CVE-2026-77214 scores CVSS 8.3 (v4.0), rated high. EPSS puts the chance of exploitation in the next 30 days at 0.32%.

What does CVE-2026-77214 affect?

CVE-2026-77214 affects libexpat libexpat.

8.3 High

libexpat before commit 13c5f63 contains a heap buffer over-read vulnerability in xmlparse.c.

CVE-2026-77214

libexpat before commit 13c5f63 contains a heap buffer over-read vulnerability in xmlparse.c. XMLParseBuffer advances the parse buffer end with parser->mbufferEnd += len using a caller-supplied length that is not validated against the allocated buffer size, so repeated XMLParseBuffer calls move mbufferEnd past the end of the heap allocation and subsequent parsing reads out of bounds. Reaching this path requires a parse buffer to already be present; otherwise XMLParseBuffer returns XMLERRORNOBUFFER. A buffer is present after a prior call to XMLGetBuffer, either directly (the common case) or indirectly through a prior XMLParse call that allocates the buffer internally. The over-read discloses adjacent heap memory to the calling application, recovering heap pointers, libc function pointers, and code pointers sufficient to defeat ASLR and build further exploitation primitives.

Assessment

CVSS: 8.3 (v4.0)
Severity: High
EPSS: 0.32% chance of exploitation in the next 30 days
Known exploited: Not listed in CISA KEV
Exploit availability: Nothing found in Exploit-DB, Metasploit, Nuclei or public PoC repositories
Published: 7 October 2026
Last updated: 8 November 2026
Affected: libexpat · libexpat
Assigner: VulnCheck

CVSS vectorCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:N/VA:L/SC:N/SI:N/SA:N

At the source

EUVD (ENISA)

References

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