NULL pointer dereference in Netsurf-Browser Libcss
CVE-2026-116740
libcss through 0.9.2 contains a NULL pointer dereference vulnerability in mq_parse_media_query() that allows remote attackers to crash consumers by supplying media lists ending in a comma. Attackers can serve a stylesheet whose @media or @import media list has a trailing comma, causing NetSurf or other parsers to crash.
Published .
CVSS v3 metric
CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H.
EPSS exploit prediction
No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.
Affected products
Weakness classification (CWE)
References
- github.com/netsurf-browser/libcss/commit/006ffc4096040da13690abc380e5f828ec0828… (patch)
- github.com/netsurf-browser/libcss (product)
- github.com/netsurf-browser/libcss/blob/release/0.9.2/src/parse/mq.c (technical-description)
- hackmd.io/@haindpwn/libcss-media-list-null-deref (third-party-advisory)
- www.vulncheck.com/advisories/libcss-through-0.9.2-null-pointer-dereference-via-… (third-party-advisory)
Frequently asked questions
- What is CVE-2026-116740?
- CVE-2026-116740 is a medium-severity vulnerability in Netsurf-Browser Libcss, classified under NULL Pointer Dereference. CVSS score: 6.5/10. Published 2026-10-26.
- How severe is CVE-2026-116740?
- Medium severity. CVSS v3 base score is 6.5 out of 10.