CVE-2026-111139
CVE-2026-111139
NetSurf libnsbmp through 0.1.7 contains an out-of-bounds read vulnerability in bmp_decode_mask() that allows attackers to read one byte past the image buffer by supplying crafted ICO files. Attackers can provide an ICO whose inner bitmap width is not a multiple of 8, causing a heap over-read that can crash applications calling bmp_decode().
Vulnerability class: Buffer Overflow
Published .
CVSS v3 metric
CVSS v3 base score 5.5 (Medium). Vector: CVSS:3.1/AV:L/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.
Weakness classification (CWE)
References
- hackmd.io/@haind-pwn/libnsbmp-rle-absolute-pad-and-ico-mask-oob-read (technical-description, exploit)
- github.com/netsurf-browser/libnsbmp/blob/ea063c9f46acb43e90208da14073332b505ef7… (technical-description)
- download.netsurf-browser.org/libs/releases/libnsbmp-0.1.7-src.tar.gz (product)
- github.com/netsurf-browser/libnsbmp (product)
- www.vulncheck.com/advisories/netsurf-libnsbmp-through-0.1.7-out-of-bounds-read-… (third-party-advisory)
Frequently asked questions
- What is CVE-2026-111139?
- CVE-2026-111139 is a medium-severity vulnerability, classified under Out-of-bounds Read. CVSS score: 5.5/10. Published 2026-10-15.
- How severe is CVE-2026-111139?
- Medium severity. CVSS v3 base score is 5.5 out of 10.