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Fencer Vulns
medium 6.3

CVE-2020-37268 json

Coq and Rocq Prover Print Assumptions Omits Unsafe Universe Checking Inlined Through Parameter Inline

published 2026-08-24 2 mo ago modified 2026-10-26 14 d ago also EUVD-2020-31263

cvss
6.3
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 7%
public exploits
0
none known

Summary

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.

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2020-37268 updated cvss 6.3

coq: rocq: Coq and Rocq Provers: Logical inconsistency bypass via Print Assumptions omission

  • Red Hat All currently supported Red Hat products
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
Proof of concept is public
Automatable
no
Technical impact
partial
Assessed
2 mo ago

Exploit prediction

0.18% chance of exploitation in the next 30 days, higher than 7% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • github.com https://github.com/rocq-prover/rocq/issues/12155 referenced PoC, tagged "exploit" by a source, unverified
  • github.com https://github.com/endrazine/rocq-cve-poc-12155 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 4.0 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
CNA 3.1 6.3 CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:C/C:N/I:H/A:N
CNA 4.0 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/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

Affected products

  • rocq-prover rocq

Classification

Weakness

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.