CVE-2026-56864
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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
INFO
Published Date :
Aug. 13, 2026, 10:17 p.m.
Last Modified :
Aug. 13, 2026, 10:17 p.m.
Remotely Exploit :
No
Source :
[email protected]
Affected Products
The following products are affected by CVE-2026-56864
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
No affected product recoded yet
Solution
- Remove go.sum and vendor directory.
- Run 'go mod tidy'.
- Ensure GOSUMDB is trusted.
- Monitor module sources for compromise.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-56864.
| URL | Resource |
|---|---|
| https://go.dev/cl/815000 | |
| https://go.dev/cl/815020 | |
| https://go.dev/issue/80745 | |
| https://groups.google.com/g/golang-announce/c/94pEornpRlI | |
| https://pkg.go.dev/vuln/GO-2026-6180 |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-56864 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-56864
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-56864 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-56864 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
New CVE Received by [email protected]
Aug. 13, 2026
Action Type Old Value New Value Added Affected [{'vendor': 'Go toolchain', 'product': 'cmd/go', 'versions': [{'status': 'affected', 'version': '0', 'lessThan': '1.25.13', 'versionType': 'semver'}, {'status': 'affected', 'version': '1.26.0-0', 'lessThan': '1.26.6', 'versionType': 'semver'}, {'status': 'affected', 'version': '1.27.0-0', 'lessThan': '1.27.0-rc.3', 'versionType': 'semver'}], 'packageName': 'cmd/go', 'collectionURL': 'https://pkg.go.dev', 'defaultStatus': 'unaffected'}, {'vendor': 'golang.org/x/mod', 'product': 'golang.org/x/mod/sumdb', 'versions': [{'status': 'affected', 'version': '0', 'lessThan': '0.40.0', 'versionType': 'semver'}], 'packageName': 'golang.org/x/mod/sumdb', 'collectionURL': 'https://pkg.go.dev', 'defaultStatus': 'unaffected', 'programRoutines': [{'name': 'Client.Lookup'}]}] Added 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 Added Reference https://go.dev/cl/815000 Added Reference https://go.dev/cl/815020 Added Reference https://go.dev/issue/80745 Added Reference https://groups.google.com/g/golang-announce/c/94pEornpRlI Added Reference https://pkg.go.dev/vuln/GO-2026-6180