CVE-2026-56864CWE-347

CVE-2026-56864

High · published August 14, 2026

CVSS v3.1
7.5
EPSS
0%
Percentile
21.3
In the wild
Unconfirmed
What it is

A malicious GOSUMDB was capable of serving arbitrary module content not contained within the transparency log. This attack allows for a coordinating GOPROXY and GOSUMDB to serve a client malicious module content that cannot be detected by evaluating the transparency log. In order to determine if you have been affected: rm -r go.sum go.work.sum vendor/ && go mod tidy

The record
Technical detail
CVSS v3.1
7.5 · HIGH
Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
CVSS v4.0
Not supplied
EPSS
0.00298 · 21.3th percentile
Weakness
CWE-347 · Improper Verification of Cryptographic Signature
Published
2026-08-14T02:17Z
References (5)
EPSS history
Timeline
  • 13 AUG 21:58Z
    Ignore unrelated, unauthenticated hashes in Lookup in golang.org/x/mod/sumdb
    cvelistv5