Is there a public exploit for CVE-2026-93990?

No public exploit for CVE-2026-93990 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-2026-93990?

CVE-2026-93990 scores CVSS 8.7 (v4.0), rated high. EPSS puts the chance of exploitation in the next 30 days at 0.4%.

What does CVE-2026-93990 affect?

CVE-2026-93990 affects libexpat libexpat.

8.7 High

Expat before 2.8.5 fails to validate that a high surrogate in UTF-16 input is followed by a low surrogate, allowing malformed UTF-16…

CVE-2026-93990

Expat before 2.8.5 fails to validate that a high surrogate in UTF-16 input is followed by a low surrogate, allowing malformed UTF-16 sequences to be accepted. Attackers can supply UTF-16 encoded XML containing lone high surrogates that consume the following code unit, causing Expat to pass unpaired surrogates to applications built with XMLUNICODE and to silently replace input characters in other builds.

Assessment

CVSS: 8.7 (v4.0)
Severity: High
EPSS: 0.4% 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: 19 September 2026
Last updated: 8 November 2026
Affected: libexpat · libexpat
Assigner: VulnCheck

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

At the source

EUVD (ENISA)

References

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