CVE-2026-111138

Description

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.

References

• https://download.netsurf-browser.org/libs/releases/libnsbmp-0.1.7-src.tar.gz
• https://github.com/netsurf-browser/libnsbmp
• https://github.com/netsurf-browser/libnsbmp/blob/ea063c9f46acb43e90208da14073332b505ef7e7/src/libnsbmp.c#L1096-L1147
• https://github.com/netsurf-browser/libnsbmp/blob/ea063c9f46acb43e90208da14073332b505ef7e7/src/libnsbmp.c#L942-L982
• https://hackmd.io/@haind-pwn/libnsbmp-rle-absolute-pad-and-ico-mask-oob-read