CVE-2020-37268
What it is
Print Assumptions does not report that a definition was produced while universe checking was disabled when that definition reaches the caller through Parameter Inline in a module type. Applying a functor inlines the body of the parameter, and the inlining drops the record that the term was built under Unset Universe Checking, so the resulting constant carries no trace of the unsafe operation. A module implementation can therefore prove False using a universe inconsistency, expose it through an inlined parameter, and have Print Assumptions report the dependent proof as closed under the global context. Because Print Assumptions is the in-process audit used to confirm that a development rests on no unexpected assumptions, a dependency built this way passes that audit while proving arbitrary propositions. The standalone checker coqchk does reject the resulting compiled file. The project records this in dev/doc/critical-bugs.md under non-fixed bugs and rates the risk as moderate when coqchk is not used.
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
- No patch or advisory is linked yet. Look at mitigations or restrict exposure.
Timeline
- ReservedThe CVE id was reserved by its CNA
- 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: none linked yet, which raises it.
Details
- Published
- Last modified
- Exploit probability
- 0.2% · EPSS, next 30 days
- Weakness
- CWE-778
- 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-2020-37268.md and follow it. Check whether this project is affected by CVE-2020-37268. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.
References
- https://github.com/endrazine/rocq-cve-poc-12155
- https://github.com/rocq-prover/rocq
- https://github.com/rocq-prover/rocq/blob/master/dev/doc/critical-bugs.md
- https://github.com/rocq-prover/rocq/issues/12155
- https://www.vulncheck.com/advisories/coq-and-rocq-prover-print-assumptions-omits-unsafe-universe-checking-inlined-through-parameter-inline
- http://www.openwall.com/lists/oss-security/2026/10/26/8
- https://github.com/rocq-prover/rocq/issues/12155