Reference page — cumulative record through Saturday, October 3, 2026 UTC. Reference pages update as the archive grows; only dated daily editions are immutable pages of record.

CVE-2026-72703

CVE-2026-72703MEDIUM

rocq-prover rocq — Rocq Prover 8.20 before 9.2.0 Guard Checker Accepts Non-Terminating Fixpoint via Unchecked Cross-Calls

  AV  AC  AT  PR  UI  VC  VI  VA   CVSS    EPSS   %ile   KEV
   L   L   N   N   P   N   H   N    6.8   .0018    6.5     —

AFFECTED
  Product  Versions  Fixed
  rocq     8.20 –    —

TIMELINE
  Aug 10  Reserved by VulnCheck
  Aug 24  EXPLOIT PUBLISHED — CVE-2026-72703 (rocq-prover rocq). Public exploit reference added.
  Aug 24  Published (CNA: VulnCheck)
  Aug 26  EXPLOIT PUBLISHED — CVE-2026-72703 (rocq-prover rocq). Public exploit reference added.
  Aug 29  EXPLOIT PUBLISHED — CVE-2026-72703 (rocq-prover rocq). Public exploit reference added.
  Sep 24  EXPLOIT PUBLISHED — CVE-2026-72703 (rocq-prover rocq). Public exploit reference added.

CWE-670 · CNA: VulnCheck · CVSS v4.0 · 5 references · NVD 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.

Lifecycle

Complete event history — 6 events, chronological
Date	Event	Detail
August 10, 2026	Reserved	Reserved by VulnCheck
August 24, 2026	EXPLOIT PUBLISHED	EXPLOIT PUBLISHED — CVE-2026-72703 (rocq-prover rocq). Public exploit reference added.
August 24, 2026	Published	Published (CNA: VulnCheck)
August 26, 2026	EXPLOIT PUBLISHED	EXPLOIT PUBLISHED — CVE-2026-72703 (rocq-prover rocq). Public exploit reference added.
August 29, 2026	EXPLOIT PUBLISHED	EXPLOIT PUBLISHED — CVE-2026-72703 (rocq-prover rocq). Public exploit reference added.
September 24, 2026	EXPLOIT PUBLISHED	EXPLOIT PUBLISHED — CVE-2026-72703 (rocq-prover rocq). Public exploit reference added.

Affected

Affected products and packages — 1 row
Vendor	Product / Package	Ecosystem	Version introduced	Fixed
rocq-prover	rocq	—	8.20	—

Weaknesses

CWE-670

References (5)

https://github.com/endrazine/rocq-cve-poc-21682 [exploit]
https://github.com/rocq-prover/rocq [product]
https://github.com/rocq-prover/rocq/issues/21682 [issue-tracking]
https://github.com/rocq-prover/rocq/pull/21684 [issue-tracking, patch]
https://www.vulncheck.com/advisories/rocq-prover-before-guard-checker-accepts-non-terminating-fixpoint-via-unchecked-cross-calls [third-party-advisory]

Authoritative record: CVE-2026-72703 at cve.org

Vendors: rocq-prover

Weaknesses: CWE-670

About this page

This is a reference page, not a dated page of record. It assembles the complete lifecycle of CVE-2026-72703 from the CVE Program record, NVD enrichment, the CISA KEV catalog, EPSS, and OSV advisories. The box score's numbers (CVSS, EPSS, KEV status) are current as of Saturday, October 3, 2026 UTC and are re-derived as the archive grows; only dated daily editions are immutable pages of record. The authoritative source for this identifier is cve.org.