# CVE-2025-62518: astral-tokio-tar Vulnerable to PAX Header Desynchronization

CVE-2025-62518 is fixed in 2 products on 1 platform, first by DEBIAN-CVE-2025-62518, released October 21, 2025. It is not reported as exploited. Patch Radar priority: High.

- Web page: https://patchblox.com/security/cve/CVE-2025-62518
- Priority: High
- CVSS: 8.1 (Important)
- EPSS: 0.0070
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Oct 21, 2025
- Weakness: Access of Resource Using Incompatible Type ('Type Confusion')
- Vendor advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-62518

## Description

astral-tokio-tar is a tar archive reading/writing library for async Rust. Versions of astral-tokio-tar prior to 0.5.6 contain a boundary parsing vulnerability that allows attackers to smuggle additional archive entries by exploiting inconsistent PAX/ustar header handling. When processing archives with PAX-extended headers containing size overrides, the parser incorrectly advances stream position based on ustar header size (often zero) instead of the PAX-specified size, causing it to interpret file content as legitimate tar headers. This issue has been patched in version 0.5.6. There are no workarounds.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | python-uv opensuse-leap 16.0 | 0.7.18-160000.3.1 | [OPENSUSE-SU-2026:20026-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-20026-1.md) | Jan 13, 2026 |
| Linux | python-uv sles 16.0 | 0.7.18-160000.3.1 | [SUSE-SU-2026:20077-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-20077-1.md) | Jan 13, 2026 |
| Linux | rust-astral-tokio-tar Debian 14 | 0.5.6-1 | [DEBIAN-CVE-2025-62518](https://patchblox.com/security/data/fix/linux/debian-cve-2025-62518.md) | Oct 21, 2025 |

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Data as of 2026-11-09T07:25:28Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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