CVE-2026-33055Public exploitNetwork attack vector

Archive content smuggling via ignored PAX size override

Published Mar 20, 2026 · Updated Mar 20, 2026

Archive parser inconsistency in tar-rs 0.4.44 and earlier allows remote attackers to smuggle differing contents through PAX headers. EntriesFields in src/archive.rs applies a PAX size override only when the base header size is zero, so a nonzero mismatch advances by the wrong length and exposes a hidden entry. Exploitation requires a crafted archive to cross parsers and be processed by a user or user-initiated workflow; the demonstrated result is a symlink visible only to tar-rs.

CVSS severity5.1
Medium
EPSS probability0.40%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Archive parser inconsistency in tar-rs 0.4.44 and earlier allows remote attackers to smuggle differing contents through PAX headers. EntriesFields in src/archive.rs applies a PAX size override only when the base header size is zero, so a nonzero mismatch advances by the wrong length and exposes a hidden entry. Exploitation requires a crafted archive to cross parsers and be processed by a user or user-initiated workflow; the demonstrated result is a symlink visible only to tar-rs.

The record

CVE
CVE-2026-33055
Published
Mar 20, 2026
Updated
Mar 20, 2026
Vendor
composefs
Product
tar-rs
Classifications
CWE-843
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

Compare your product and version with the public record. A matching version still requires validation against your environment.

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

8.1National Vulnerability DatabaseCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N
5.1GitHub, Inc.CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N
5.1RustSec Advisory DatabaseCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:L/VI:L/VA:N/SC:N/SI:N/SA: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-843Access of Resource Using Incompatible Type ('Type Confusion')

Public exploit references

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

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo