What’s Vulnerable › Vulnerabilities
CVE-2026-48101: GHSL-2026-117: 7-Zip UEFI Capsule uninitialized heap memory disclosure
- Severity: medium (CVSS 6.5 v3.1)
- Exploited in the wild: not listed in CISA KEV
- EPSS: 0.3% probability of exploitation in the next 30 days
- Public exploit or detection template: yes
- Published: 2026-06-05 · updated 2026-06-17
- Weakness: CWE-908
Description
7-Zip is a file archiver with a high compression ratio. Versions 9.21 through 26.00 contain an An uninitialized memory disclosure vulnerability in the UEFI capsule (.scap) parser in 7-Zip. The OpenCapsule function allocates a heap buffer of attacker-declared CapsuleImageSize (up to 1 GiB) without zero-initialization, then reads the file contents into it with ReadStream_FALSE whose return value is silently discarded. If the file is truncated, the unread tail of the buffer retains uninitialized heap memory, which is then exposed as extracted file content via GetStream. Version 26.0.1 fixes the issue.
Affected products
- 7-Zip: from 9.21 before 26.01 — fixed in 26.01
How to fix
Upgrade to a fixed version: 7-Zip 26.01. Check the vendor advisory for mitigations.
References
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