# CVE-2026-56865: Fix transparency log tile verification bypass in golang.org/x/mod/sumdb/tlog CVE-2026-56865 is fixed in 20 products on 2 platforms, first by SUSE-SU-2026:3640-1, released August 18, 2026. It is not reported as exploited. Patch Radar priority: High. - Web page: https://patchblox.com/security/cve/CVE-2026-56865 - Priority: High - CVSS: 8.4 (Important) - EPSS: 0.0013 - CISA KEV: not listed - Exploited (vendor report): no - Publicly disclosed: no - Published: Aug 13, 2026 - Weakness: Improper Verification of Cryptographic Signature - Vendor advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-56865 ## Description A malicious GOPROXY was previously capable of forging up to two sumdb tiles that allow for a requested module to bypass the GOSUMDB check and persist attacker-controlled module content to a local Go module cache. This attack allows for a malicious GOPROXY to serve malicious module content that cannot be detected by evaluating the transparency log. All tiles are now correctly verified against their parents. In order to determine if you have been affected: rm -r go.sum go.work.sum vendor/ && go mod tidy ## Where it's fixed | Platform | Product | Fixed in | Fix | Released | |---|---|---|---|---| | Windows apps | Go Programming Language | 1.27.3 | [Go Programming Language 1.27.3](https://patchblox.com/security/data/fix/windows-app/golang.go-1.27.3.md) | Oct 19, 2026 | | Linux | go1.25 opensuse-leap 16.0 | 1.25.13-160000.1.1 | [OPENSUSE-SU-2026:21592-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21592-1.md) | Aug 19, 2026 | | Linux | go1.25 sles 15.6 | 1.25.13-150000.1.50.1 | [SUSE-SU-2026:3640-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-3640-1.md) | Aug 18, 2026 | | Linux | go1.25 sles 15.7 | 1.25.13-150000.1.50.1 | [SUSE-SU-2026:3640-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-3640-1.md) | Aug 18, 2026 | | Linux | go1.25 sles 16.0 | 1.25.13-160000.1.1 | [SUSE-SU-2026:23300-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-23300-1.md) | Aug 19, 2026 | | Linux | go1.25-openssl opensuse-leap 16.0 | 1.25.14-160000.1.1 | [OPENSUSE-SU-2026:21696-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21696-1.md) | Aug 30, 2026 | | Linux | go1.25-openssl sles 15.6 | 1.25.14-150600.13.27.1 | [SUSE-SU-2026:3815-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-3815-1.md) | Aug 26, 2026 | | Linux | go1.25-openssl sles 15.7 | 1.25.14-150600.13.27.1 | [SUSE-SU-2026:3815-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-3815-1.md) | Aug 26, 2026 | | Linux | go1.25-openssl sles 16.0 | 1.25.14-160000.1.1 | [SUSE-SU-2026:23573-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-23573-1.md) | Aug 30, 2026 | | Linux | go1.26 opensuse-leap 16.0 | 1.26.6-160000.1.1 | [OPENSUSE-SU-2026:21593-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21593-1.md) | Aug 19, 2026 | | Linux | go1.26 sles 15.6 | 1.26.6-150000.1.24.1 | [SUSE-SU-2026:3641-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-3641-1.md) | Aug 18, 2026 | | Linux | go1.26 sles 15.7 | 1.26.6-150000.1.24.1 | [SUSE-SU-2026:3641-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-3641-1.md) | Aug 18, 2026 | | Linux | go1.26 sles 16.0 | 1.26.6-160000.1.1 | [SUSE-SU-2026:23301-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-23301-1.md) | Aug 19, 2026 | | Linux | go1.26-openssl opensuse-leap 16.0 | 1.26.7-160000.1.1 | [OPENSUSE-SU-2026:21705-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21705-1.md) | Aug 30, 2026 | | Linux | go1.26-openssl sles 15.6 | 1.26.7-150600.13.15.1 | [SUSE-SU-2026:3816-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-3816-1.md) | Aug 26, 2026 | | Linux | go1.26-openssl sles 15.7 | 1.26.7-150600.13.15.1 | [SUSE-SU-2026:3816-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-3816-1.md) | Aug 26, 2026 | | Linux | go1.26-openssl sles 16.0 | 1.26.7-160000.1.1 | [SUSE-SU-2026:23576-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-23576-1.md) | Aug 30, 2026 | | Linux | go1.27 sles 15.6 | 1.27.0-150000.1.6.1 | [SUSE-SU-2026:3830-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-3830-1.md) | Aug 26, 2026 | | Linux | go1.27 sles 15.7 | 1.27.0-150000.1.6.1 | [SUSE-SU-2026:3830-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-3830-1.md) | Aug 26, 2026 | | Linux | golang amzn 2023 | 1.26.7-1.amzn2023.0.1 | [ALAS2023-2026-2114](https://patchblox.com/security/data/fix/linux/alas2023-2026-2114.md) | Aug 31, 2026 | | Linux | golang-1.22 Ubuntu 22.04.1 LTS (jammy) | 1.22.2-2~22.04.4 | [golang-1.22 1.22.2-2~22.04.4](https://patchblox.com/security/data/fix/linux/ubuntu-jammy-golang-1.22-1.22.2-2-22.04.4.md) | Oct 20, 2026 | | Linux | golang-1.22 Ubuntu 24.04.5 LTS (noble) | 1.22.2-2ubuntu0.5 | [golang-1.22 1.22.2-2ubuntu0.5](https://patchblox.com/security/data/fix/linux/ubuntu-noble-golang-1.22-1.22.2-2ubuntu0.5.md) | Oct 20, 2026 | | Linux | golang-1.22-go Ubuntu 22.04.1 LTS (jammy) | 1.22.2-2~22.04.4 | [golang-1.22-go 1.22.2-2~22.04.4](https://patchblox.com/security/data/fix/linux/ubuntu-jammy-golang-1.22-go-1.22.2-2-22.04.4.md) | Oct 20, 2026 | | Linux | golang-1.22-go Ubuntu 24.04.5 LTS (noble) | 1.22.2-2ubuntu0.5 | [golang-1.22-go 1.22.2-2ubuntu0.5](https://patchblox.com/security/data/fix/linux/ubuntu-noble-golang-1.22-go-1.22.2-2ubuntu0.5.md) | Oct 20, 2026 | | Linux | golang-1.22-src Ubuntu 22.04.1 LTS (jammy) | 1.22.2-2~22.04.4 | [golang-1.22-src 1.22.2-2~22.04.4](https://patchblox.com/security/data/fix/linux/ubuntu-jammy-golang-1.22-src-1.22.2-2-22.04.4.md) | Oct 20, 2026 | | Linux | golang-1.22-src Ubuntu 24.04.5 LTS (noble) | 1.22.2-2ubuntu0.5 | [golang-1.22-src 1.22.2-2ubuntu0.5](https://patchblox.com/security/data/fix/linux/ubuntu-noble-golang-1.22-src-1.22.2-2ubuntu0.5.md) | Oct 20, 2026 | | Linux | golang-1.26 Debian 14 | 1.26.6-1 | [DEBIAN-CVE-2026-56865](https://patchblox.com/security/data/fix/linux/debian-cve-2026-56865.md) | Aug 27, 2026 | | Linux | golang-1.27 Debian 14 | 1.27~rc3-1 | [DEBIAN-CVE-2026-56865](https://patchblox.com/security/data/fix/linux/debian-cve-2026-56865.md) | Aug 27, 2026 | | Linux | golang-bin amzn 2023 | 1.26.7-1.amzn2023.0.1 | [ALAS2023-2026-2114](https://patchblox.com/security/data/fix/linux/alas2023-2026-2114.md) | Aug 31, 2026 | | Linux | golang-docs amzn 2023 | 1.26.7-1.amzn2023.0.1 | [ALAS2023-2026-2114](https://patchblox.com/security/data/fix/linux/alas2023-2026-2114.md) | Aug 31, 2026 | | Linux | golang-misc amzn 2023 | 1.26.7-1.amzn2023.0.1 | [ALAS2023-2026-2114](https://patchblox.com/security/data/fix/linux/alas2023-2026-2114.md) | Aug 31, 2026 | | Linux | golang-shared amzn 2023 | 1.26.7-1.amzn2023.0.1 | [ALAS2023-2026-2114](https://patchblox.com/security/data/fix/linux/alas2023-2026-2114.md) | Aug 31, 2026 | | Linux | golang-src amzn 2023 | 1.26.7-1.amzn2023.0.1 | [ALAS2023-2026-2114](https://patchblox.com/security/data/fix/linux/alas2023-2026-2114.md) | Aug 31, 2026 | | Linux | golang-tests amzn 2023 | 1.26.7-1.amzn2023.0.1 | [ALAS2023-2026-2114](https://patchblox.com/security/data/fix/linux/alas2023-2026-2114.md) | Aug 31, 2026 | | Linux | govulncheck-vulndb opensuse-leap 16.0 | 0.0.20260827T195228-160000.1.1 | [OPENSUSE-SU-2026:21761-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21761-1.md) | Sep 4, 2026 | | Linux | govulncheck-vulndb sles 16.0 | 0.0.20260827T195228-160000.1.1 | [SUSE-SU-2026:23625-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-23625-1.md) | Sep 4, 2026 | | Linux | helm opensuse-leap 16.0 | 4.3.0-160000.1.1 | [OPENSUSE-SU-2026:21983-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21983-1.md) | Sep 30, 2026 | | Linux | helm sles 16.0 | 4.3.0-160000.1.1 | [SUSE-SU-2026:23984-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-23984-1.md) | Sep 30, 2026 | --- Data as of 2026-11-08T19:12:23Z UTC. 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