Golang/x/crypto message forgery vulnerability

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

5.9 · CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N

EPSS

• CVE-2019-11841: 2.00% estimated exploitation activity in the next 30 days; percentile 80.80 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

A message-forgery issue was discovered in crypto/openpgp/clearsign/clearsign.go in supplementary Go cryptography libraries 2019-03-25. According to the OpenPGP Message Format specification in RFC 4880 chapter 7, a cleartext signed message can contain one or more optional "Hash" Armor Headers. The "Hash" Armor Header specifies the message digest algorithm(s) used for the signature. However, the Go clearsign package ignores the value of this header, which allows an attacker to spoof it. Consequently, an attacker can lead a victim to believe the signature was generated using a different message digest algorithm than what was actually used. Moreover, since the library skips Armor Header parsing in general, an attacker can not only embed arbitrary Armor Headers, but also prepend arbitrary text to cleartext messages without invalidating the signatures.

Published by the source

24 May 2022, 16:46 UTC

Last modified by the source

2 Oct 2023, 15:42 UTC

Source last checked

26 Oct 2026, 14:59 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-x3jr-pf6g-c48f

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# Patch Next advisory brief: CVE-2019-11841

Advisory: Golang/x/crypto message forgery vulnerability
IDs: CVE-2019-11841, GHSA-x3jr-pf6g-c48f
Record: https://patchnext.com/advisories/cve-2019-11841 (revision 1, source checked 26 Oct 2026, 14:59 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 5.9)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: golang.org/x/crypto 0.0.0-20190424203555-c05e17bb3b2d. A vendor fix does not mean a deployment is fixed.

## Affected components
- Go golang.org/x/crypto: affected < 0.0.0-20190424203555-c05e17bb3b2d; fixed in 0.0.0-20190424203555-c05e17bb3b2d

## Suggested inspection (read-only)
- Go golang.org/x/crypto: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on golang.org/x/crypto.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-x3jr-pf6g-c48f (GitHub-reviewed advisory GHSA-x3jr-pf6g-c48f lists affected ranges: Go golang.org/x/crypto >=0 <0.0.0-20190424203555-c05e17bb3b2d)

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