CVE-2026-56865 (GCVE-0-2026-56865)
Vulnerability from cvelistv5
Published
2026-08-13 21:58
Modified
2026-08-14 15:34
Summary
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
Impacted products
Vendor Product Version
Go toolchain cmd/go Version: 0   
Version: 1.26.0-0   
Version: 1.27.0-0   
Create a notification for this product.
Show details on NVD website


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          "url": "https://go.dev/cl/815020"
        },
        {
          "url": "https://pkg.go.dev/vuln/GO-2026-6179"
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      "title": "Fix transparency log tile verification bypass in golang.org/x/mod/sumdb/tlog"
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Sightings

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Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or seen somewhere by the user.
  • Confirmed: The vulnerability is confirmed from an analyst perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
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  • Patched: This vulnerability was successfully patched by the user reporting the sighting.
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  • Not confirmed: The user expresses doubt about the veracity of the vulnerability.
  • Not patched: This vulnerability was not successfully patched by the user reporting the sighting.


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