Reachable Assertion in rulex

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

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

EPSS

• CVE-2022-31100: 0.88% estimated exploitation activity in the next 30 days; percentile 59.11 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Impact When parsing untrusted rulex expressions, rulex may crash, possibly enabling a Denial of Service attack. This happens when the expression contains a multi-byte UTF-8 code point in a string literal or after a backslash, because rulex tries to slice into the code point and panics as a result. This is a security concern for you, if - your service parses untrusted rulex expressions (expressions provided by an untrusted user), and - your service becomes unavailable when the thread running rulex panics. Patches The crashes are fixed in version 0.4.3. Affected users are advised to update to this version. Workarounds You can use catchunwind to recover from panics. For more information If you have any questions or comments about this advisory: Open an issue in rulex Email me at ludwig.stecher@gmx.de Credits Credit for finding these bugs goes to - cargo fuzz and afl.rs - evanrichter - ForAllSecure Mayhem

Published by the source

21 Jun 2022, 20:12 UTC

Last modified by the source

27 Jan 2023, 05:04 UTC

Source last checked

26 Oct 2026, 15:33 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-8v9w-p43c-r885

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# Patch Next advisory brief: CVE-2022-31100

Advisory: Reachable Assertion in rulex
IDs: CVE-2022-31100, GHSA-8v9w-p43c-r885
Record: https://patchnext.com/advisories/cve-2022-31100 (revision 1, source checked 26 Oct 2026, 15:33 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 6.5)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: rulex 0.4.3. A vendor fix does not mean a deployment is fixed.

## Affected components
- crates.io rulex: affected < 0.4.3; fixed in 0.4.3

## Suggested inspection (read-only)
- crates.io rulex: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on rulex.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-8v9w-p43c-r885 (GitHub-reviewed advisory GHSA-8v9w-p43c-r885 lists affected ranges: crates.io rulex >=0 <0.4.3)

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