CVSS 4.0
8.7 highCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:NCVE-2026-93990
High (8.7). EPSS 0.4% chance of exploitation in the next 30 days.
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 XML_UNICODE and to silently replace input characters in other builds.
Severity
CVSS 3.1
7.5 highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N- EPSS
- 0.4% chance of exploitation in the next 30 days; higher than 34% of CVEs (scores of 2026-10-31)
- CWE
- CWE-176
- Published
- Modified
- Record from
- the NVD, synced