CVE-2022-31100 — rulex is a new, portable, regular expression language

rulex is a new, portable, regular expression language. 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, becaus

01What is this vulnerability?

rulex is a new, portable, regular expression language. 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…

02Affected products

Vendor	Product	Versions
rulex-rs	rulex	< 0.4.3

03Active exploitation status

Not currently listed on the CISA Known Exploited Vulnerabilities (KEV) catalog. EPSS is the best forward-looking signal — see the EPSS row above.

04Recommended remediation

• Patch to a fixed version listed in the vendor advisory (see references below).
• Mitigate with WAF rules, network egress filters, or feature flags where the patch is not yet available.
• Hunt historical logs for exploitation indicators — see Detection signatures below.

05Technical details

For the full vendor write-up, exploit chains, and reference implementations, see the references list in section 09.

06Detection signatures

Ask SARA in chat to draft a starting detection for this CVE in your stack of choice.

07Related CVEs

No directly-cited follow-up CVEs in the KB record for this advisory. The references list in section 09 carries the vendor cross-references.

08Timeline

• Published: 2022-06-27T22:10:11.000Z
• Last modified: 2025-04-23T18:06:26.973Z

09References

• github.com — https://github.com/rulex-rs/rulex/security/advisories/GHSA-8v9w-p43c-r885
• github.com — https://github.com/rulex-rs/rulex/commit/fac6d58b25c6f9f8c0a6cdc4dec75b37b219f1d…