CVE-2026-111138: Out-of-bounds Read in NetSurf libnsbmp
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.
CVSS v4.0
Score 6.8medium
Affected software
NetSurf
libnsbmp
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AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
NetSurf libnsbmp versions up to and including 0.1.7 contain an out-of-bounds read vulnerability in the bmp_decode_rle8() and bmp_decode_rle4() functions. The vulnerability arises because the absolute-run bound checks fail to account for the word-alignment pad byte, allowing a crafted RLE8 or RLE4 BMP image ending on an odd-length absolute run to trigger a one-byte heap over-read. This can lead to application crashes when decoding maliciously crafted BMP images.
Potential Impact
The vulnerability can cause a one-byte heap over-read, resulting in application crashes when decoding specially crafted RLE8 or RLE4 BMP images. There is no indication of code execution or data corruption beyond the crash. The CVSS 4.0 base score is 6.8 (medium severity), reflecting local attack vector with low complexity and no privileges required but requiring user interaction.
Mitigation Recommendations
No patch or official fix information is provided in the available data. Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until a fix is available, avoid processing untrusted BMP images with libnsbmp versions up to 0.1.7 to mitigate risk.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- VulnCheck
- Date Reserved
- 2026-10-15T17:03:55.771Z
- Cvss Version
- 4.0
- State
- PUBLISHED
Threat ID: 6ad123b42cdf04f65652b6f7
Added to database: 10/15/2026, 19:04:20 UTC
Last enriched: 10/15/2026, 19:48:54 UTC
Last updated: 10/15/2026, 20:04:10 UTC
Views: 3
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