CVE-2021-38194

highpriority · track · 39EPSS 0.013 · 70 %ileEUUS
grimoire priorityP2 · Scheduled
Exploitable?
—
no known exploitation
Likely / severe?
1.27% (70th) EPSS
CVSS 7.5 · high
Is it mine?
4 products
Check your exposure
Who says so?
4 sources
cnnvd · enisa_euvd · osv · nvd

EPSS · scored 2026-10-26

An issue was discovered in the ark-r1cs-std crate before 0.3.1 for Rust. It does not enforce any constraints in the FieldVar::mul_by_inverse method. Thus, a prover can produce a proof that is unsound but is nonetheless verified.

01

cvss

Technical severity, 0–10. One row per scoring source.

9.8
010

base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · high–critical · 7.5–9.8

v2.07.5highAV:N/AC:L/Au:N/C:P/I:P/A:Pprimary · NVD / NIST USexploitability 10 · impact 6.4
v3.19.8criticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:Hprimary · NVD / NIST USexploitability 3.9 · impact 5.9
v3.19.8criticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:Hsecondary · OSV
v3.19criticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:Usecondary · CVSS-BT (t0sche)
02

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-682US
03

affected products (4)

Products and version ranges known to be affected.

04

advisories (2)

Vendor and ecosystem advisories describing this.

  • GHSA-qj3v-q2vj-4c8hCalculation error in ark-r1cs-std2021-08-25ghsa · osvUS

    An issue was discovered in the ark-r1cs-std crate before 0.3.1 for Rust. It does not enforce any constraints in the FieldVar::mul_by_inverse method. Thus, a prover can produce a proof that is unsound but is nonetheless verified.

  • RUSTSEC-2021-0075Flaw in `FieldVar::mul_by_inverse` allows unsound R1CS constraint systems2021-07-08vendor · osvUS

    Versions `0.2.0` to `0.3.0` of ark-r1cs-std did not enforce any constraints in the `FieldVar::mul_by_inverse` method, allowing a malicious prover to produce an unsound proof that passes all verifier checks. This method was used primarily in scalar multiplication for [`short_weierstrass::ProjectiveVar`](https://docs.rs/ark-r1cs-std/0.3.0/ark_r1cs_std/groups/curves/short_weierstrass/struct.ProjectiveVar.html). This bug was fixed in commit `47ddbaa`, and was released as part of version `0.3.1` on `crates.io`.

05

also known as (5)

Other names and identifiers for this entity.

06

sources

Which sources assert this record, and when.

cnnvdenisa_euvdosvnvdNVDCVE.orgMITRE
published 2021-08-08modified 2026-06-17
07

references (6)

External citations — patches, advisories, analysis.

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