CVE-2026-56864
published 2026-08-13CVE-2026-56864: A malicious GOSUMDB was capable of serving arbitrary module content not contained within the transparency log. This attack allows for a coordinating GOPROXY…
PriorityP346high7.5CVSS 3.1
AVNACLPRNUINSUCHINAN
EPSS
0.30%
21.3th percentile
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
Affected
13 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| advanced-cluster-security | rhacs-main-rhel9 | — | — |
| advanced-cluster-security | rhacs-rhel9-operator | — | — |
| edo | external-dns-rhel9 | — | — |
| go_toolchain | cmd_go | < 1.25.13 | 1.25.13 |
| go_toolchain | cmd_go | >= 1.26.0-0 < 1.26.6 | 1.26.6 |
| go_toolchain | cmd_go | >= 1.27.0-0 < 1.27.0-rc.3 | 1.27.0-rc.3 |
| golang.org | x_mod_golang.org_x_mod_sumdb | < 0.40.0 | 0.40.0 |
| openshift-pipelines | pipelines-chains-controller-rhel9 | — | — |
| openshift-pipelines | pipelines-cli-tkn-rhel9 | — | — |
| openshift-pipelines | pipelines-operator-proxy-rhel9 | — | — |
| openshift-pipelines | pipelines-operator-webhook-rhel9 | — | — |
| openshift-pipelines | pipelines-rhel9-operator | — | — |
| rhosdt | opentelemetry-collector-rhel9 | — | — |
CVSS provenance
nvdv3.17.5HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
vendor_redhat7.5HIGH
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VulDB
Google Go cmd/go/x-mod-sumdb signature verification
vuldb·2026-08-14
CVE-2026-56864 [CRITICAL] Google Go cmd/go/x-mod-sumdb signature verification
A vulnerability identified as critical has been detected in Google Go. The affected element is an unknown function of the component cmd/go/x-mod-sumdb. This manipulation causes improper verification of cryptographic signature.
This vulnerability appears as CVE-2026-56864. The attack may be initiated remotely. There is no available exploit.
Red Hat
golang.org/x/mod/sumdb: golang.org/x/mod/sumdb: Integrity bypass via malicious GOSUMDB
vendor_redhat·2026-08-13·CVSS 7.5
CVE-2026-56864 [HIGH] CWE-494 golang.org/x/mod/sumdb: golang.org/x/mod/sumdb: Integrity bypass via malicious GOSUMDB
golang.org/x/mod/sumdb: golang.org/x/mod/sumdb: Integrity bypass via malicious GOSUMDB
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
A flaw was found in golang.org/x/mod/sumdb. A malicious Go checksum database (GOSUMDB) can serve arbitrary module content that is not recorded in the transparency log. This allows a coordinated Go proxy (GOPROXY) and GOSUMDB to deliver malicious module content to a client, which cannot be detected by examining the transparency log. This vul
No detection rules found.
No public exploits indexed.
Bugzilla
CVE-2026-56864 golang-x-mod: golang.org/x/mod/sumdb: Integrity bypass via malicious GOSUMDB [fedora-all]
bugzilla·2026-10-21·CVSS 7.5
CVE-2026-56864 [HIGH] CVE-2026-56864 golang-x-mod: golang.org/x/mod/sumdb: Integrity bypass via malicious GOSUMDB [fedora-all]
CVE-2026-56864 golang-x-mod: golang.org/x/mod/sumdb: Integrity bypass via malicious GOSUMDB [fedora-all]
Disclaimer: Community trackers are created by Red Hat Product Security team on a best effort basis. Package maintainers are required to ascertain if the flaw indeed affects their package, before starting the update process.
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
Bugzilla
CVE-2026-56864 golang-x-mod: golang.org/x/mod/sumdb: Integrity bypass via malicious GOSUMDB [epel-all]
bugzilla·2026-10-21·CVSS 7.5
CVE-2026-56864 [HIGH] CVE-2026-56864 golang-x-mod: golang.org/x/mod/sumdb: Integrity bypass via malicious GOSUMDB [epel-all]
CVE-2026-56864 golang-x-mod: golang.org/x/mod/sumdb: Integrity bypass via malicious GOSUMDB [epel-all]
Disclaimer: Community trackers are created by Red Hat Product Security team on a best effort basis. Package maintainers are required to ascertain if the flaw indeed affects their package, before starting the update process.
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
Bugzilla
CVE-2026-56864 golang.org/x/mod/sumdb: golang.org/x/mod/sumdb: Integrity bypass via malicious GOSUMDB
bugzilla·2026-08-13·CVSS 7.5
CVE-2026-56864 [HIGH] CVE-2026-56864 golang.org/x/mod/sumdb: golang.org/x/mod/sumdb: Integrity bypass via malicious GOSUMDB
CVE-2026-56864 golang.org/x/mod/sumdb: golang.org/x/mod/sumdb: Integrity bypass via malicious GOSUMDB
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
Discussion:
Changed to IMPORTANT - 8.1 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N from CRITICAL - 9.6 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H.
CVSS Justification
* S:C -> S:U
- The failure is in checksum/transparency-log verification inside the Go module client; impact is on module trust and build integrity in that s
2026-08-13
Published