libexpat -- Improper Handling of Unicode Encoding

2026-10-04 · CVE-2026-93990 · VuXML entry

https://github.com/libexpat/libexpat/pull/1282 reports: 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 …

Affected versions

• expat < 2.8.5

By system

1 still vulnerable, 1 fixed. Where VuXML applies (FreeBSD, DragonFly, FreeBSD's derivatives) a port is vulnerable while its version is in a range; pkgsrc says itself whether it lists a CVE of this advisory; OpenBSD and MidnightBSD keep no list this site reads, so their row is only an estimate: FreeBSD's ranges applied to upstream's version.