CVE-2026-33056Public exploitNetwork attack vector

Directory permission modification via symlink-following chmod

Published Mar 20, 2026 · Updated Mar 20, 2026

Symlink following in composefs tar-rs 0.4.44 and earlier allows attackers to change permissions on directories outside an extraction root. In unpack_dir, an EEXIST path check calls fs::metadata(), follows an archive-created symlink, accepts its target as a directory, and later applies the entry's mode with chmod. A crafted archive must be unpacked; the demonstrated consequence is directory-mode modification, not file-content access or code execution.

CVSS severity5.1
Medium
EPSS probability0.38%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Symlink following in composefs tar-rs 0.4.44 and earlier allows attackers to change permissions on directories outside an extraction root. In unpack_dir, an EEXIST path check calls fs::metadata(), follows an archive-created symlink, accepts its target as a directory, and later applies the entry's mode with chmod. A crafted archive must be unpacked; the demonstrated consequence is directory-mode modification, not file-content access or code execution.

The record

CVE
CVE-2026-33056
Published
Mar 20, 2026
Updated
Mar 20, 2026
Vendor
composefs
Product
tar-rs
Classifications
CWE-61, T1222.002
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Mar 20, 2026CVE publishedPublication date reported by the CVE source.
  2. Mar 20, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 0.4.45

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

composefs · tar-rsversion=< 0.4.45

Published CVSS scores

5.1GitHub, Inc.CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N
6.5NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-61UNIX Symbolic Link (Symlink) Following
T1222.002Linux and Mac File and Directory Permissions Modification

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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