CVE-2026-32766 — astral-tokio-tar
Fix: astral-sh/tokio-tar@e5e0139CVE-2026-32766 is a CWE-436 vulnerability in astral-tokio-tar. A fix is available for astral-tokio-tar — see the affected versions and patch details below.
astral-tokio-tar insufficiently validates PAX extensions during extraction
Exploitation Status
No confirmed exploitation observed yet
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for CVE-2026-32766.
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
Real-World Exposure
astral-tokio-tarReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects crates.io packages — download data is not available via public APIs for these ecosystems.
Description
astral-tokio-tar is a tar archive reading/writing library for async Rust. In versions 0.5.6 and earlier, malformed PAX extensions were silently skipped when parsing tar archives. This silent skipping (rather than rejection) of invalid PAX extensions could be used as a building block for a parser differential, for example by silently skipping a malformed GNU “long link” extension so that a subsequent parser would misinterpret the extension. In practice, exploiting this behavior in astral-tokio-tar requires a secondary misbehaving tar parser, i.e. one that insufficiently validates malformed PAX extensions and interprets them rather than skipping or erroring on them. This vulnerability is considered low-severity as it requires a separate vulnerability against any unrelated tar parser. This issue has been fixed in version 0.6.0.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🦀crates.io | astral-tokio-tar | all versions | 0.6.0cargo update -p astral-tokio-tar --precise 0.6.0 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for astral-tokio-tar, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update astral-tokio-tar to 0.6.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-32766 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2026-32766 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2026-32766. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-32766 in your dependencies?
O3 Security finds CVE-2026-32766 across crates.io dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.