CVE-2026-33055: tar-rs is a tar archive reading/writing library for Rust. Versions 0.4.44 and below have conditional logic that skips the PAX size header in cases whe...

Description

tar-rs is a tar archive reading/writing library for Rust. Versions 0.4.44 and below have conditional logic that skips the PAX size header in cases where the base header size is nonzero. As part of CVE-2025-62518, the astral-tokio-tar project was changed to correctly honor PAX size headers in the case where it was different from the base header. This is almost the inverse of the astral-tokio-tar issue. Any discrepancy in how tar parsers honor file size can be used to create archives that appear differently when unpacked by different archivers. In this case, the tar-rs (Rust tar) crate is an outlier in checking for the header size - other tar parsers (including e.g. Go archive/tar) unconditionally use the PAX size override. This can affect anything that uses the tar crate to parse archives and expects to have a consistent view with other parsers. This issue has been fixed in version 0.4.45.

Metrics

CVSS 3.1

8.1/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N

CVSS 4.0

5.1/10

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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

EPSS Probability

0.40%

31.5th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-843

Affected Software

Vendor	Product	Versions
Alexcrichton	Tar-Rs	< 0.4.45

References

https://github.com/alexcrichton/tar-rs/commit/de1a5870e603758f430073688691165f21a33946Patch
https://github.com/alexcrichton/tar-rs/security/advisories/GHSA-gchp-q4r4-x4ffExploit, Vendor Advisory
https://www.cve.org/CVERecord?id=CVE-2025-62518Third Party Advisory

Timeline

Published: Mar 20, 2026
Last Modified: Jun 17, 2026
Status: Analyzed

Frequently Asked Questions

What is CVE-2026-33055?

tar-rs is a tar archive reading/writing library for Rust. Versions 0.4.44 and below have conditional logic that skips the PAX size header in cases where the base header size is nonzero. As part of CVE-2025-62518, the astral-tokio-tar project was changed to correctly honor PAX size headers in the case where it was different from the base header. This is almost the inverse of the astral-tokio-tar issue. Any discrepancy in how tar parsers honor file size can be used to create archives that appear differently when unpacked by different archivers. In this case, the tar-rs (Rust tar) crate is an outlier in checking for the header size - other tar parsers (including e.g. Go archive/tar) unconditionally use the PAX size override. This can affect anything that uses the tar crate to parse archives and expects to have a consistent view with other parsers. This issue has been fixed in version 0.4.45.

How severe is CVE-2026-33055?

CVE-2026-33055 has a CVSS score of 5.1/10 (MEDIUM severity). The EPSS model estimates a 0.40% probability of exploitation in the next 30 days.

How do I fix CVE-2026-33055?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.