CVE-2026-48101

GHSL-2026-117: 7-Zip UEFI Capsule uninitialized heap memory disclosure

MEDIUM
6.5
CVSS Score
Published: June 5, 2026 at 03:17 PM UTC
Updated: June 17, 2026 at 10:54 AM UTC
2 products affected across 2 vendorsZip 7-zip7-Zip

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Severity
MEDIUM6.5
Exploit prediction
EPSS 0.3%
SSVC
No known exploit

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

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

9.21 ≤ v < 26.01
Affected range stops below 26.01, so it looks safe — our inference, not a vendor statement
v < 26.01
Affected range stops below 26.01, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

References (1)

x_refsource_CONFIRMExploitPatchThird Party Advisory
Source: cverecord
https://securitylab.github.com/advisories/GHSL-2026-115_GHSL-2026-122_7-zip/

SSVC — Action Prioritization

SSVCNo known exploitNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

6.5MEDIUMGitHub_M
Attack Vector
NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
REQUIRED
Scope
UNCHANGED
Confidentiality
HIGH
Integrity
NONE
Availability
NONE
Vector?

Quick Info

StatusANALYZED
CWE
CWE-908

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