Vulnerability · Published Sep 2, 2026 · Assigned by GitHub_M
CVE-2026-53600async-tar PAX extension-header desync enables tar entry/content smuggling
Medium 6.3
In plain English
A medium-severity improper input validation in async-tar from dignifiedquire. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 39% of all known vulnerabilities).
Official description
async-tar is a tar archive reading/writing library for async Rust. Prior to version 0.6.1, async-tar mis-applies a buffered PAX size extension to an intermediary extension header (a GNU longname L, a GNU longlink K, or a PAX x/g header) instead of to the next file entry. POSIX requires a PAX extended-header record set to describe the next file entry, never an intervening extension header. Because poll_next_raw (src/archive.rs) threads the buffered PAX records into the size computation of whatever raw header it reads next — and that header can be an intermediary L — the stream cursor is advanced by an attacker-chosen amount when the L body is consumed. The parser then desyncs relative to a POSIX-correct tar parser (e.g. GNU tar), reading subsequent bytes at the wrong block boundary. This issue has been patched in version 0.6.1.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:13 | rust-async-tar | no fix listed | DEBIAN-CVE-2026-53600 |
| Ubuntu:24.04:LTS | rust-async-tar | no fix listed | UBUNTU-CVE-2026-53600 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| dignifiedquire | async-tar | < 0.6.1 |
Weakness: CWE-20, CWE-843 · Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N
References
- https://github.com/dignifiedquire/async-tar/security/advisories/GHSA-35rm-7j9c-2f7m x_refsource_CONFIRM
- https://github.com/dignifiedquire/async-tar/releases/tag/v0.6.1 x_refsource_MISC