CVE-2026-117680

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CVE-2026-117680

Summary: jsv treats regex match budget exhaustion as a non-match, bypassing patternProperties and not

Details: Improper Check for Unusual or Exceptional Conditions vulnerability in the pattern and patternProperties keywords in lud jsv allows an unauthenticated remote attacker to bypass schema validation via a string that matches a schema regex only after heavy backtracking. JSV.Helpers.RegexExt.bounded_match?/2 runs schema regexes with a backtracking budget but calls :re.run/3 without :report_errors, so a match that exhausts the budget returns the same :nomatch as a real non-match. A key that matches a patternProperties regex is then checked against additionalProperties or not at all, and a string that matches a not subschema with a pattern is accepted. Before the budget existed, Regex.match?/2 failed the same way at Erlang's default match limit. Only schemas whose regex explores a catastrophic branch before the branch that matches are affected. The attacker controls the data, not the schema, and linear patterns never exhaust the budget. This issue affects jsv: from 0.1.0 before 0.26.2.

References: https://cna.erlef.org/cves/CVE-2026-117680.html, https://github.com, https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/117xxx/CVE-2026-117680.json, https://github.com/lud/jsv, https://github.com/lud/jsv/commit/302a5d0803468f81a1cf08e3b67d8b14cee759ca, https://github.com/lud/jsv/commit/defdb8a68ac7f218aa5dfe85190d484017cb8817, https://github.com/lud/jsv/security/advisories/GHSA-cvmg-hgv6-jqcp, https://nvd.nist.gov/vuln/detail/CVE-2026-117680, https://osv.dev/vulnerability/EEF-CVE-2026-117680, https://repo.hex.pm