CVE-2020-37268CWE-778

CVE-2020-37268

Medium · published August 25, 2026

CVSS v3.1
6.3
EPSS
0%
Percentile
2.1
In the wild
Unconfirmed
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.

The record
Technical detail
CVSS v3.1
6.3 · MEDIUM
Vector
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:C/C:N/I:H/A:N
CVSS v4.0
6.8 · 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
EPSS
0.00120 · 2.1th percentile
Weakness
CWE-778 · Insufficient Logging
Published
2026-08-25T00:16Z
References (6)
EPSS history
Timeline
  • 26 AUG 05:04Z
    EPSS moved — → 0%
    epss
  • 24 AUG 20:08Z
    Coq and Rocq Prover Print Assumptions Omits Unsafe Universe Checking Inlined Through Parameter Inline
    cvelistv5