6.9

CVE-2025-62375: in-toto go-witness Improper Certificate Validation

CVSS: 6.9v4.0MediumDeferred
AliasesCGA-3j9x-f9qq-j4c9CGA-7jwv-3gcx-p9rxCGA-fc63-p387-xgf4
Published 15-10-2025Last modified 15-10-2025
Open JSON

Vulnerability summary

CVE-2025-62375 is a medium (CVSS 6.9) Improper Certificate Validation vulnerability in in-toto go-witness. EPSS estimates a 0.20% chance of exploitation in the next 30 days, higher than 9.7% of scored vulnerabilities.

Overall risk
28/100
0100
Medium · default modelHow is this calculated?
CVSS score
6.9/10
010
Medium · v4.0 (CVE.org)
EPSS score
0.20%
0%100%
Low · 0.00 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 2 · Related 5
OPENSUSE-SU-2025:15710-1OPENSUSE-SU-2026:21483-1CGA-3WM9-9VC6-W2W8CGA-6P38-CJWP-5RWXCGA-J2VV-JPG8-7695

Timeline

  1. 15-10-2025
    PublishedVulnerability first disclosed.
  2. 15-10-2025
    Last modifiedVulnerability information updated.

Description

go-witness and witness are Go modules for generating attestations. In go-witness versions 0.8.6 and earlier and witness versions 0.9.2 and earlier the AWS attestor improperly verifies AWS EC2 instance identity documents. Verification can incorrectly succeed when a signature is not present or is empty, and when RSA signature verification fails. The attestor also embeds a single legacy global AWS public certificate and does not account for newer region specific certificates issued in 2024, making detection of forged documents difficult without additional trusted region data. An attacker able to supply or intercept instance identity document data (such as through Instance Metadata Service impersonation) can cause a forged identity document to be accepted, leading to incorrect trust decisions based on the attestation. This is fixed in go-witness 0.9.1 and witness 0.10.1. As a workaround, manually verify the included identity document, signature, and public key with standard tools (for example openssl) following AWS’s verification guidance, or disable use of the AWS attestor until upgraded.

CVSS metrics

5 scores · 5 sources · 1 version

EPSS trend

Probability

0.20%

Chance of exploitation in the next 30 days

Percentile

10%

Versus all other CVEs

30-day change

0.00 pp

From 0.20% on 20-09-2026

20-09-202620-10-2026
EPSS score
0.20%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Chainguard4 products
  • tekton-chains< 0.25.1-r7
  • tekton-chains-fips< 0.25.1-r6
  • tkn< 0.42.0-r3
  • tkn-fips< 0.42.0-r2
Wolfi2 products
  • tekton-chains< 0.25.1-r7
  • tkn< 0.42.0-r3
Github.com/in-toto1 product
  • go-witness< 0.9.1
In-toto1 product

4 vendors · 8 products

References

5 links