7.1
HIGH CVSS 4.0
CVE-2026-116740
libcss through 0.9.2 NULL Pointer Dereference via Media-Query Parser
Description

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.

INFO

Published Date :

Oct. 26, 2026, 10:16 p.m.

Last Modified :

Oct. 26, 2026, 10:16 p.m.

Remotely Exploit :

Yes !
Affected Products

The following products are affected by CVE-2026-116740 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

No affected product recoded yet

CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 3.1 MEDIUM 83251b91-4cc7-4094-a5c7-464a1b83ea10
CVSS 3.1 MEDIUM [email protected]
CVSS 4.0 HIGH 83251b91-4cc7-4094-a5c7-464a1b83ea10
CVSS 4.0 HIGH [email protected]
Solution
Update libcss to a version that addresses the NULL pointer dereference in mq_parse_media_query().
  • Update libcss to a patched version.
  • Apply security patches for libcss.
  • Recompile applications using updated libcss.
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-116740 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-116740 weaknesses.

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-116740 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2026-116740 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • New CVE Received by [email protected]

    Oct. 26, 2026

    Action Type Old Value New Value
    Added Description 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.
    Added CVSS V4.0 AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
    Added CVSS V3.1 AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
    Added CWE CWE-476
    Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/116xxx/CVE-2026-116740.json">CVE-2026-116740</a>
    Added Reference https://github.com/netsurf-browser/libcss
    Added Reference https://github.com/netsurf-browser/libcss/blob/release/0.9.2/src/parse/mq.c#L984
    Added Reference https://github.com/netsurf-browser/libcss/commit/006ffc4096040da13690abc380e5f828ec08284d
    Added Reference https://hackmd.io/@haindpwn/libcss-media-list-null-deref
    Added Reference https://www.vulncheck.com/advisories/libcss-through-0.9.2-null-pointer-dereference-via-media-query-parser
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.