7.5

CVE-2026-56864: Ignore unrelated, unauthenticated hashes in Lookup in golang.org/x/mod/sumdb

Awaiting analysis
AliasesUBUNTU-CVE-2026-56864DEBIAN-CVE-2026-56864CGA-22gv-8cpr-jqc8
Published 13-08-2026Last modified 14-08-2026

Vulnerability summary

CVE-2026-56864 is a high (CVSS 7.5) vulnerability in go toolchain cmd/go. EPSS estimates a 0.30% chance of exploitation in the next 30 days, higher than 22.5% of scored vulnerabilities.

Priority
Prioritisesevere

Severe, CVSS 7.5 (CVE.org); no exploitation reported by the 5 checked sources; EPSS 0% (FIRST, 03-11-2026)

Source freshness unavailable

How is this decided?
CVSS score
7.5/10
010
High · v3.1 (CVE.org)
EPSS score
0.30%
0%100%
Low · 0.00 pp in 30 days
KEVNot listedNot listed by any tracked catalog.
RansomwareNot flaggedNo ransomware use recorded.
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 30 · Related 30
MGASA-2026-0341OPENSUSE-SU-2026:11516-1OPENSUSE-SU-2026:11517-1OPENSUSE-SU-2026:11536-1OPENSUSE-SU-2026:11575-1OPENSUSE-SU-2026:11871-1

Timeline

  1. 13-08-2026
    PublishedVulnerability first disclosed.
  2. 14-08-2026
    Last modifiedVulnerability information updated.

Description

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

CVSS metrics

5 scores · 5 sources · 1 version

EPSS trend

Probability

0.30%

Chance of exploitation in the next 30 days

Percentile

23%

Versus all other CVEs

30-day change

No change 0.00 pp

From 0.30% on 04-10-2026

04-10-202603-11-2026

Known exploited

Compare KEV catalogs
CISA KEV

Not in the CISA KEV catalog.

ENISA CNW

Not in the ENISA CNW catalog.

CIRCL

Not in the CIRCL catalog.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Version check

Known conditions: network-reachable, no authentication, no user interaction (CVSS vector). Other conditions: not stated in public data.

Chainguard199 products
  • aactl< 0.4.12-r69
  • agentbeatAll versions (No fix recorded)
  • agentbeat-fipsAll versions (No fix recorded)
  • amazon-cloudwatch-agentAll versions (No fix recorded)
  • amazon-eks-amiAll versions (No fix recorded)
Alpine1 product
  • go< 1.26.8-r0

2 vendors · 200 products · Showing 200 of 1636

References

10 links