CVE-2026-72703

What it is

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.

At a glance

Exploitability

Can be exploited locally on the machine without logging in, but needs a user to act. High risk of data tampering.

Exploit odds

0.2% chance of exploitation in the next 30 days (EPSS).

Fix

A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

1. 2026-08-24 20:17 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-10-26 02:17 UTC Last updatedMost recent change to the record

Why it ranks here

• Exploited in the wild: no, CISA does not list it.
• Exploit odds: 0.2% in the next 30 days (EPSS).
• Severity: 6.8 MEDIUM (CVSS).
• Fix: a patch or advisory is linked.

Details

Published

2026-08-24 20:17 UTC

Last modified

2026-10-26 02:17 UTC

Exploit probability

0.2% · EPSS, next 30 days

Weakness

CWE-670

Record status

Deferred

Attack profile CVSS 4.0 · 6.8

Attack vector

Local

Complexity

Low

Attack requirements

None

Privileges needed

None

User interaction

Passive

Confidentiality

None

Integrity

High

Availability

None

Is it in your code?

Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.

Read https://cve-list.com/agent/cve/CVE-2026-72703.md and follow it. Check whether this project is affected by CVE-2026-72703. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

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