CVE-2026-25920
SumatraPDF has a heap out-of-bounds read in MOBI HuffDic decompressor
Vexday Risk Score
13Low
SSVC decision (CISA)
Track
No exploitation signal → monitor
CVSS 5.5EPSS 0.2%KEV nãoPoC —Nuclei —Metasploit —Patch —
Lifecycle
09 Feb 2026Published on NVD
Recommendation: Monitor — no exploitation signal at the moment.
SumatraPDF is a multi-format reader for Windows. In 3.5.2 and earlier, a heap out-of-bounds read vulnerability exists in SumatraPDF's MOBI HuffDic decompressor. The bounds check in AddCdicData() only validates half the range that DecodeOne() actually accesses. Opening a crafted .mobi file can read nearly (1 << codeLength) bytes beyond the CDIC dictionary buffer, leading to a crash.
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
Affected products
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