libexpat before 2.8.3 has an out-of-bounds read and resultant infinite loop because low surrogates are treated the same as high surrogates during Unicode processing in the *_toUtf16 functions.
https://github.com/libexpat/libexpat/pull/1296
https://bugzilla.mozilla.org/show_bug.cgi?id=2053153
Source: Mitre, NVD
Published: 2026-08-10
Updated: 2026-08-10
Base Score: 4.9
Vector: CVSS2#AV:L/AC:L/Au:N/C:N/I:N/A:C
Severity: Medium
Base Score: 6.2
Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS: 0.00153