CVE-2026-48102
Description
7-Zip is a file archiver with a high compression ratio. Versions 9.11 through 26.00 contain a heap out-of-bounds read of up to 3 bytes in the UDF disc image handler's File Identifier Descriptor parser. In CFileId::Parse (CPP/7zip/Archive/Udf/UdfIn.cpp), after validating size < 38 + idLen + impLen and advancing processed to 38 + impLen + idLen, the alignment-padding loop reads p[processed] while incrementing up to 3 times to reach a 4-byte boundary, and the processed <= size bounds check only runs after the loop. When (38 + impLen + idLen) % 4 != 0 and 38 + impLen + idLen == size, the loop reads 1 to 3 bytes past the end of the exact-size heap buffer allocated via buf.Alloc((size_t)item.Size). The UDF handler is registered for .iso and .udf files and auto-detected by signature, and the OOB read triggers during Open() when listing or extracting a crafted UDF image. Impact is limited to information disclosure (a 1-bit oracle per OOB byte via open/fail behavior) and denial of service (crash under hardened allocators); there is no write primitive. Version 26.01 fixes the issue.
How to fix CVE-2026-48102
To remediate CVE-2026-48102, upgrade the affected package to a fixed version below.
- —upgrade to 22.01+really26.01+dfsg-0+deb12u1 or later
- —upgrade to 16.02+really26.01+dfsg-0+deb11u1 or later
Is CVE-2026-48102 being exploited?
Low — EPSS is 0.2%, meaning exploitation activity has not been observed at scale.
Affected packages (2)
- from 0, < 22.01+really26.01+dfsg-0+deb12u1
- from 0, < 16.02+really26.01+dfsg-0+deb11u1
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 3.1 | MEDIUM4.3 | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N |