7-Zip: Out-of-bounds Read
CVE-2026-48092 is a high-severity out-of-bounds read vulnerability in 7-Zip from Mcmilk, with a CVSS 3.1 base score of 8.1 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, but only if a user takes part, for example by opening a link or file. Affected 7-Zip versions: >= 9.34, < 26.01. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 2.74% chance of exploitation within 30 days, higher than 86% of scored CVEs.
High severity with no evidence of exploitation so far.
What to do
- Check which version of 7-Zip you run against the affected versions below, and install the vendor's latest release.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
- Because the attack needs a user to take part, warn users about unexpected links and files related to this product until it is patched.
Affected products and versions
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- RequiredA user must take an action such as opening a file or link.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- NoneNothing can be modified.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 4.3 | Medium | CNA (github.com) |
| CVSS 3.1 | 8.1 | High | NVD |
Official description
7-Zip is a file archiver with a high compression ratio. Versions 9.34 through 26.00 contain a heap memory disclosure via SquashFS fragment offset integer overflow on 32-bit builds. 32-bit integer overflow in the SquashFS ReadBlock function allows an attacker-controlled node.Offset value to bypass the fragment bounds check, causing memcpy to read heap memory preceding the cache buffer into the extracted file. The vulnerability is exploitable only on 32-bit builds of 7-Zip where size_t is 32 bits, allowing the addition offsetInBlock + blockSize to wrap modulo 2³². On 64-bit builds the addition is promoted to 64 bits and the check correctly rejects the input. Version 26.01 patches the issue.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Out-of-bounds Read
The product reads data past the end, or before the beginning, of the intended buffer.
How developers prevent this class of flaw
- Use a language that provides appropriate memory abstractions.
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: poc, automatable: no, technical impact: partial).
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
- securitylab.github.com/advisories/GHSL-2026-115_GHSL-2026-122_7-zip/Exploit, Third Party Advisory
Other vulnerabilities in 7-Zip
- 7.1 High severity
- 7.1 High severity
- 8.8 High severity
Recent Out-of-bounds Read vulnerabilities
- 8.8 High severity
- 8.8 High severity
- 8.3 High severity
- 8.8 High severity
- 8.1 High severity
- 8.8 High severity
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