Out-of-bounds Read in Netsurf Libnsbmp
CVE-2026-111138
NetSurf libnsbmp through 0.1.7 contains an out-of-bounds read vulnerability in bmp_decode_rle8() and bmp_decode_rle4() because absolute-run bound checks omit the word-alignment pad byte. Attackers can supply a crafted RLE8 or RLE4 BMP ending on an odd-length absolute run to cause a one-byte heap over-read, crashing applications decoding untrusted images.
Vulnerability class: Buffer Overflow
Published · last modified .
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.
Affected products
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)
- 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-2026-111138?
- CVE-2026-111138 is a medium-severity vulnerability in Netsurf Libnsbmp, classified under Out-of-bounds Read. CVSS score: 5.5/10. Published 2026-10-15.
- How severe is CVE-2026-111138?
- Medium severity. CVSS v3 base score is 5.5 out of 10.