How severe is CVE-2022-31100?

CVE-2022-31100 has a CVSS score of 6.5/10, rated MEDIUM. Review your exposure and patch according to your risk tolerance.

Which packages are affected by CVE-2022-31100?

CVE-2022-31100 affects the following packages: rulex (crates.io). Ecosystems affected: crates.io.

How do I fix CVE-2022-31100?

Update rulex to 0.4.3 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2022-31100 is resolved across your whole dependency graph.

How do I detect CVE-2022-31100 in my crates.io dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for rulex, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate CVE-2022-31100 if there is no patch (or I can't update yet)?

Cap what an attacker can consume: apply request size, rate and timeout limits in front of the affected component, and run it with memory and CPU limits so exhaustion degrades one worker rather than the whole service.

Is CVE-2022-31100 actively exploited in the wild?

No public exploit code has been indexed for CVE-2022-31100 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for CVE-2022-31100?

CVE-2022-31100 has an EPSS (Exploit Prediction Scoring System) score of 0.9%, placing it in the 59th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is CVE-2022-31100?

CVE-2022-31100 is classified as Reachable Assertion (CWE-617). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was CVE-2022-31100 published, and has it been updated?

CVE-2022-31100 was published on June 27, 2022 and was last updated on October 28, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

🦀

🦀 crates.io

Not in CISA KEV

MEDIUM severity

CVE-2022-31100 — rulex

MEDIUMFix: rulex-rs/rulex@fac6d58

CVE-2022-31100 is a medium-severity (CVSS 6.5) Reachable Assertion vulnerability in rulex. A fix is available for rulex — see the affected versions and patch details below.

Reachable Assertion in rulex

Also known asGHSA-8v9w-p43c-r885RUSTSEC-2022-0031

Published

Jun 27, 2022

Updated

Oct 28, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

Exploitation data as of Nov 5, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

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-2022-31100.

EPSS Exploitation Probability

via FIRST.org ↗

0.9%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs59th percentile — riskier than 59% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

How urgent is this, really

Where this sits among everything scored

Real-World Exposure

1 pkg affected

🦀rulex

Real-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

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 catch_unwind 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 [email protected]

Credits

Credit for finding these bugs goes to

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
🦀crates.io	`rulex`	all versions	0.4.3`cargo update -p rulex --precise 0.4.3`

Affected Products

1 product · 1 configurations

Application

pomskypomsky-lang

< 0.4.3

range

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for rulex, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update rulex to 0.4.3 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2022-31100 is resolved across your whole dependency graph.
Workarounds
Cap what an attacker can consume: apply request size, rate and timeout limits in front of the affected component, and run it with memory and CPU limits so exhaustion degrades one worker rather than the whole service.

Frequently Asked Questions

### 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 t