Reference page — cumulative record through Wednesday, August 19, 2026 UTC. Reference pages update as the archive grows; only dated daily editions are immutable pages of record.
mcmilk 7-Zip — GHSL-2026-117: 7-Zip UEFI Capsule uninitialized heap memory disclosure
AV AC PR UI S C I A CVSS EPSS %ile KEV
N L N R U H N N 6.5 .0028 20.2 —
AFFECTED
Product Versions Fixed
7-Zip >= 9.21, < 26.01 – —
TIMELINE
May 20 Reserved by GitHub_M
Jun 5 EXPLOIT PUBLISHED — CVE-2026-48101 (mcmilk 7-Zip). Public exploit reference added.
Jun 5 Published (CNA: GitHub_M)
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.
Lifecycle
Complete event history — 3 events, chronological
| Date | Event | Detail |
| May 20, 2026 | Reserved | Reserved by GitHub_M |
| June 5, 2026 | EXPLOIT PUBLISHED | EXPLOIT PUBLISHED — CVE-2026-48101 (mcmilk 7-Zip). Public exploit reference added. |
| June 5, 2026 | Published | Published (CNA: GitHub_M) |
Affected
Affected products and packages — 1 row
| Vendor | Product / Package | Ecosystem | Version introduced | Fixed |
| mcmilk | 7-Zip | — | >= 9.21, < 26.01 | — |
About this page
This is a reference page, not a dated page of record. It assembles the complete lifecycle of CVE-2026-48101 from the CVE Program record, NVD enrichment, the CISA KEV catalog, EPSS, and OSV advisories. The box score's numbers (CVSS, EPSS, KEV status) are current as of Wednesday, August 19, 2026 UTC and are re-derived as the archive grows; only dated daily editions are immutable pages of record. The authoritative source for this identifier is cve.org.