CVE-2026-72705
What it is
The guard checker in Rocq Prover does not follow recursive calls made through a fixpoint's own arguments. A fixpoint may pass itself as a higher-order argument to a second fixpoint, which then applies it to a value that is not a subterm of the structural argument. Passing the recursive function to a plain definition is rejected because the checker unfolds the definition and observes the call, but passing it to a fixpoint is accepted because higher-order recursive calls through fixpoint arguments are not tracked. This admits a type that is definitionally equal to its own negation, so self-application produces False in purely definitional code, without tactics, axioms, plugins or unsafe flags, and Print Assumptions reports the result as closed under the global context. 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
- PublishedDisclosed publicly on CVE.org and NVD
- 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
- Last modified
- 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
Raw 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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
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-2026-72705.md and follow it. Check whether this project is affected by CVE-2026-72705. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.
Fix and advisories
References
- https://github.com/endrazine/rocq-cve-poc-21683
- https://github.com/rocq-prover/rocq
- https://github.com/rocq-prover/rocq/issues/21683
- https://github.com/rocq-prover/rocq/pull/21684
- https://www.vulncheck.com/advisories/rocq-prover-before-guard-checker-accepts-fixpoint-passed-as-a-higher-order-argument
- http://www.openwall.com/lists/oss-security/2026/10/26/6