CVE-2026-48102: 7-Zip heap out-of-bounds read in UDF disc image handler

CVE-2026-48102 · Severity: low · CVSS 3.1 · Published 2026-06-05

7-Zip is a widely used file archiving utility for compressing and decompressing data. A vulnerability in its UDF disc image handler allows a specially crafted .iso or .udf file to trigger a small memory leak or a program crash. While the risk of data theft is low, an attacker could use this to crash the application or potentially gain minor insights into system memory when a user attempts to open a malicious disc image.

Technologies: 7-Zip. Vendors: 7-Zip.

Quick answers

Is CVE-2026-48102 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2026-48102 being exploited in the wild.
How severe is CVE-2026-48102?
Low severity, with a CVSS score of 3.1, published 5 June 2026.
Which products and versions are affected?
7-Zip 9.11 through 26.00.
Is there a fix for CVE-2026-48102?
A patch was published on 2026-04-27: Version 26.01 released with fixes Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-48102 attacked?
It is attacked over the network, in a software library.
Am I affected by CVE-2026-48102?
Check whether you run 7-Zip at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

Technical details

A heap out-of-bounds read exists in the CFileId::Parse function within CPP/7zip/Archive/Udf/UdfIn.cpp. The vulnerability is caused by an alignment-padding loop that increments a pointer to reach a 4-byte boundary before performing a bounds check. If a crafted UDF image specifies a size that is not 4-byte aligned and matches the current processed length, the loop reads 1 to 3 bytes past the allocated heap buffer. This can be exploited via a malicious .iso or .udf file to create a 1-bit oracle for information disclosure or cause a denial of service (crash) under hardened memory allocators. The issue is fixed in version 26.01.

Affected products

  • 7-Zip 7-Zip 9.11 through 26.00

Timeline

  • 2026-04-21: disclosed: Reported via SourceForge private issues
  • 2026-04-27: patched: Version 26.01 released with fixes
  • 2026-06-05: advisory: CVE-2026-48102 published

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