# CVE-2026-34986: Go JOSE denial of service via panic in JWE decryption

Source: https://junglewise.ai/threats/cve-2026-34986-go-jose-denial-of-service-via-panic-in-jwe-decryption  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-04-06. Updated: 2026-06-30  
License: CC BY 4.0 with a link back

CVE-2026-34986 · Severity: high · CVSS 7.5 · Published 2026-04-06

Go JOSE is a software library used by developers to handle encrypted and signed data, such as login tokens and secure messages. A flaw in how the library processes certain encrypted objects allows an attacker to send a specially crafted message that causes the application to crash. This results in a denial-of-service, potentially taking down critical authentication or data processing services.

Technologies: [github.com/go-jose/go-jose/v3 (Go)](https://junglewise.ai/threats/technologies/github-com-go-jose-go-jose-v3), [github.com/go-jose/go-jose/v4 (Go)](https://junglewise.ai/threats/technologies/github-com-go-jose-go-jose-v4). Vendors: [Go](https://junglewise.ai/threats/vendors/go).

## Quick answers

**Is CVE-2026-34986 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-34986 being exploited in the wild.

**How severe is CVE-2026-34986?** High severity, with a CVSS score of 7.5, published 6 April 2026.

**Which products and versions are affected?** github.com/go-jose/go-jose (Go) SEMVER:introduced=0,last_affected=2.6.3; github.com/go-jose/go-jose/v3 (Go) SEMVER:introduced=0,fixed=3.0.5; github.com/go-jose/go-jose/v4 (Go) SEMVER:introduced=0,fixed=4.1.4.

**Is there a fix for CVE-2026-34986?** Yes. github.com/go-jose/go-jose/v3 (Go): upgrade to 3.0.5 or later; github.com/go-jose/go-jose/v4 (Go): upgrade to 4.1.4 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-34986 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-34986?** Check whether you run github.com/go-jose/go-jose (Go), github.com/go-jose/go-jose/v3 (Go) or github.com/go-jose/go-jose/v4 (Go) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- github.com/go-jose/go-jose/v3 (Go): upgrade to 3.0.5 or later

  ```sh
  go get github.com/go-jose/go-jose/v3@v3.0.5
  ```

- github.com/go-jose/go-jose/v4 (Go): upgrade to 4.1.4 or later

  ```sh
  go get github.com/go-jose/go-jose/v4@v4.1.4
  ```


## Technical details

A vulnerability exists in Go JOSE's JWE decryption logic where the library fails to validate the length of the 'encrypted_key' field when a key wrapping algorithm (ending in 'KW') is specified. Specifically, the 'cipher.KeyUnwrap()' function in 'key_wrap.go' attempts to allocate a slice with a zero or negative length based on the empty field, triggering a Go runtime panic. This is reachable via 'ParseEncrypted', 'ParseEncryptedJSON', or 'ParseEncryptedCompact' followed by a 'Decrypt' call. The issue affects versions prior to 4.1.4 and 3.0.5. Applications are only vulnerable if they include key wrapping algorithms in their list of accepted key algorithms during parsing.

## Affected products

- Go JOSE go-jose/v3 < 3.0.5
- Go JOSE go-jose/v4 < 4.1.4

## Identifiers

- CVE-2026-34986
- GHSA-78h2-9frx-2jm8
- GO-2026-4945

## Timeline

- 2026-03-31: patched: Fixes released in versions 4.1.4 and 3.0.5
- 2026-03-31: advisory: GitHub Security Advisory published
- 2026-04-06: disclosed: CVE-2026-34986 published to NVD

## References

- [https://github.com/go-jose/go-jose/security/advisories/GHSA-78h2-9frx-2jm8](https://github.com/go-jose/go-jose/security/advisories/GHSA-78h2-9frx-2jm8)
- [https://pkg.go.dev/github.com/go-jose/go-jose/v4](https://pkg.go.dev/github.com/go-jose/go-jose/v4)
- [https://access.redhat.com/errata/RHSA-2026:10125](https://access.redhat.com/errata/RHSA-2026:10125)
- [https://access.redhat.com/errata/RHSA-2026:10130](https://access.redhat.com/errata/RHSA-2026:10130)
- [https://access.redhat.com/errata/RHSA-2026:10135](https://access.redhat.com/errata/RHSA-2026:10135)
- [https://access.redhat.com/errata/RHSA-2026:10175](https://access.redhat.com/errata/RHSA-2026:10175)
- [https://access.redhat.com/errata/RHSA-2026:11070](https://access.redhat.com/errata/RHSA-2026:11070)

## Related threats

- [Go JOSE RSA parameter validation denial of service](https://junglewise.ai/threats/cve-2026-116587-go-jose-provides-an-implementation-of-the-javascript-object)
- [Go JOSE stack overflow in JSON parsing](https://junglewise.ai/threats/cve-2026-116586-go-jose-provides-an-implementation-of-the-javascript-object)
- [Go JOSE panic on empty JWE ciphertext](https://junglewise.ai/threats/cve-2026-116585-go-jose-provides-an-implementation-of-the-javascript-object)
- [GO-2025-3485 - DoS in go-jose Parsing in github.com/go-jose/go-jose](https://junglewise.ai/threats/cve-2025-27144-dos-in-go-jose-parsing)
- [GO-2024-2631 - Decompression bomb vulnerability in github.com/go-jose/go-jose](https://junglewise.ai/threats/cve-2024-28180-go-jose-vulnerable-to-improper-handling-of-highly-compressed-data)