Go JOSE Panics in JWE decryption

Exploitation

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

CVSS

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

EPSS

• CVE-2026-34986: 0.66% estimated exploitation activity in the next 30 days; percentile 51.74 (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.

Impact Decrypting a JSON Web Encryption (JWE) object will panic if the alg field indicates a key wrapping algorithm (one ending in KW, with the exception of A128GCMKW, A192GCMKW, and A256GCMKW) and the encryptedkey field is empty. The panic happens when cipher.KeyUnwrap() in keywrap.go attempts to allocate a slice with a zero or negative length based on the length of the encryptedkey. This code path is reachable from ParseEncrypted() / ParseEncryptedJSON() / ParseEncryptedCompact() followed by Decrypt() on the resulting object. Note that the parse functions take a list of accepted key algorithms. If the accepted key algorithms do not include any key wrapping algorithms, parsing will fail and the application will be unaffected. This panic is also reachable by calling cipher.KeyUnwrap() directly with any ciphertext parameter less than 16 bytes long, but calling this function directly is less common. Panics can lead to denial of service. Fixed In 4.1.4 and v3.0.5 Workarounds If the list…

Published by the source

3 Apr 2026, 03:28 UTC

Last modified by the source

6 Apr 2026, 23:11 UTC

Source last checked

26 Oct 2026, 15:19 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-78h2-9frx-2jm8

Preview the exact text before you copy it. Commands are read-only suggestions; review them before running anything.

# Patch Next advisory brief: CVE-2026-34986

Advisory: Go JOSE Panics in JWE decryption
IDs: CVE-2026-34986, GHSA-78h2-9frx-2jm8
Record: https://patchnext.com/advisories/cve-2026-34986 (revision 1, source checked 26 Oct 2026, 15:19 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 7.5)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Partial vendor fix; fixed versions by package: github.com/go-jose/go-jose/v3 3.0.5; github.com/go-jose/go-jose/v4 4.1.4. A vendor fix does not mean a deployment is fixed.

## Affected components
- Go github.com/go-jose/go-jose/v3: affected < 3.0.5; fixed in 3.0.5
- Go github.com/go-jose/go-jose: affected <= 2.6.3
- Go github.com/go-jose/go-jose/v4: affected < 4.1.4; fixed in 4.1.4

## Suggested inspection (read-only)
- Go github.com/go-jose/go-jose/v3: check the installed version with your package manager.
- Go github.com/go-jose/go-jose: check the installed version with your package manager.
- Go github.com/go-jose/go-jose/v4: check the installed version with your package manager.

## Supported action
No complete vendor fix is recorded. Follow the primary source's mitigation guidance and check this record again before closing anything.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on github.com/go-jose/go-jose/v3, github.com/go-jose/go-jose, github.com/go-jose/go-jose/v4.
- 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-78h2-9frx-2jm8 (GitHub-reviewed advisory GHSA-78h2-9frx-2jm8 lists affected ranges: Go github.com/go-jose/go-jose/v4 >=0 =0 =0 <=2.6.3)

Commands are suggestions: review each one before running it.