CVE-2026-116585 Go JOSE: Panic during CBC-HMAC processing
- Exploited in the wild
- Not known
- Fix
- Available
What is CVE-2026-116585?
CVE-2026-116585 is a medium-severity vulnerability in go-jose, published on 26 Oct 2026.
Official description
Go JOSE provides an implementation of the Javascript Object Signing and Encryption set of standards in Go, including support for JSON Web Encryption (JWE), JSON Web Signature (JWS), and JSON Web Token (JWT) standards. Prior to 4.1.5, decrypting untrusted JWE ciphertext with A128CBC-HS256, A192CBC-HS384, or A256CBC-HS512 can pass an empty ciphertext buffer to CBC-HMAC unpadding. Insufficient validation allows the empty buffer to be indexed, causing a panic and denial of service. Applications that decrypt attacker-controlled ciphertext with one of these content-encryption algorithms are affected. This issue is fixed in version 4.1.5.
Weakness: CWE-129
Which versions are affected by CVE-2026-116585?
4 open source packages ship an affected version, including github.com/go-jose/go-jose/v3 and github.com/go-jose/go-jose/v4.
| Package | Affected | Fixed in |
|---|---|---|
github.com/go-jose/go-jose/v3 Go | All versions to 3.0.5 | None |
github.com/go-jose/go-jose/v3 Go | All versions to 3.0.5 | None |
github.com/go-jose/go-jose/v4 Go | All versions | 4.1.5 |
github.com/go-jose/go-jose/v4 Go | All versions | 4.1.5 |
How do I fix CVE-2026-116585?
Upgrade to a fixed version.
Is CVE-2026-116585 being exploited?
There is no known exploitation of CVE-2026-116585 in the wild and no public exploit code.
Sources
Also known as GHSA-4w3g-jfj2-cw2q, MINI-22gq-jqh7-rg24, MINI-2fhf-jg85-23q3, MINI-2gwq-7cx7-99r7, MINI-2p59-v5vw-74gx, MINI-2vj7-hg8g-cc82 and 51 more.