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🐍 PyPI

GHSA-h92m-42h4-82f6

MEDIUM

postfix-mta-sts-resolver Algorithm Downgrade vulnerability

Also known asCVE-2019-16791PYSEC-2020-174
Published
Jul 5, 2019
Updated
Mar 13, 2026
Affected
1 pkg
Patched
1 / 1
Exploits
None indexed

Blast Radius

1 pkg affected
🐍postfix-mta-sts-resolver

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects PyPI packages — download data is not available via public APIs for these ecosystems.

Description

Incorrect query parsing

Impact

All users of versions prior to 0.5.1 can receive incorrect response from daemon under rare conditions, rendering downgrade of effective STS policy.

Patches

Problem has been patched in version 0.5.1

Workarounds

Users may remediate this vulnerability without upgrading by applying these patches to older suppoorted versions.

For more information

If you have any questions or comments about this advisory:

Affected Packages

1 total 1 fixed
EcosystemPackageVulnerable rangeFix
🐍PyPIpostfix-mta-sts-resolverall versions0.5.1

Detection & mitigation playbook

Open-source dependency
  1. Detect

    Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for postfix-mta-sts-resolver. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.

  2. Fix

    Update postfix-mta-sts-resolver to 0.5.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-h92m-42h4-82f6 is resolved across your whole dependency graph.

  3. 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.

  4. How O3 protects you

    O3 pinpoints whether GHSA-h92m-42h4-82f6 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Tailored to GHSA-h92m-42h4-82f6. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

## Incorrect query parsing ### Impact All users of versions prior to 0.5.1 can receive incorrect response from daemon under rare conditions, rendering downgrade of effective STS policy. ### Patches Problem has been patched in version 0.5.1 ### Workarounds Users may remediate this vulnerability without upgrading by applying [these patches](https://gist.github.com/Snawoot/b9da85d6b26dea5460673b29df1adc6b) to older suppoorted versions. ### For more information If you have any questions or comments about this advisory: * Open an issue in [postfix-mta-sts-resolver repo](https://github.com/Snawo
O3 Security · Impact-Aware SCA

Is GHSA-h92m-42h4-82f6 in your dependencies?

O3 detects GHSA-h92m-42h4-82f6 across PyPI dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.