{"cve":"CVE-2026-72703","nvd":{"published":"2026-08-24T20:17:18.240","modified":"2026-10-26T02:17:07.063","status":"Deferred","description":"The guard checker in Rocq Prover treats a parameter of a nested mutual fixpoint as uniform without examining calls between the different bodies of that fixpoint. find_uniform_parameters in kernel/inductive.ml inspects only self-recursive calls, so when no body calls itself the function concludes that every parameter is uniform. A parameter that grows through a cross-call from one body to another therefore keeps the subterm specification it inherited from the enclosing fixpoint, and a recursive call guarded by that specification is accepted although the argument is not structurally smaller. A non-terminating definition is admitted as structurally decreasing, which yields a term whose value equals its own successor and so a proof of False, from which any proposition follows. The proof requires no axioms, plugins or unsafe flags and Print Assumptions reports it as closed under the global context. Introduced in Coq 8.20 and fixed in Rocq 9.2.0.","cvss_v4":{"vector":"CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N","score":6.8},"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:C/C:N/I:H/A:N","score":6.3},"cwes":["CWE-670"],"references":["https://github.com/endrazine/rocq-cve-poc-21682","https://github.com/rocq-prover/rocq","https://github.com/rocq-prover/rocq/issues/21682","https://github.com/rocq-prover/rocq/pull/21684","https://www.vulncheck.com/advisories/rocq-prover-before-guard-checker-accepts-non-terminating-fixpoint-via-unchecked-cross-calls"],"products":[],"source":"nvd","synced_at":"2026-10-26T02:37:26.505365588+00:00"},"epss":{"cve":"CVE-2026-72703","score":0.00176,"percentile":0.07063,"date":"2026-10-25"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}