CVE-2026-34986 Go JOSE affect by a panic in JWE decryption

What is CVE-2026-34986?

CVE-2026-34986 is a high-severity denial of service vulnerability in go-jose, published on 6 Apr 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

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 4.1.4 and 3.0.5, 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 encrypted_key field is empty. The panic happens when cipher.KeyUnwrap() in key_wrap.go attempts to allocate a slice with a zero or negative length based on the length of the encrypted_key. 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. This vulnerability is fixed in 4.1.4 and 3.0.5.

Weakness: CWE-131, CWE-248

Which versions are affected by CVE-2026-34986?

8 open source packages ship an affected version, including github.com/go-jose/go-jose/v3, github.com/go-jose/go-jose and github.com/go-jose/go-jose/v4. It affects 1 product.

Products include Go-Jose Project Go-Jose.

How do I fix CVE-2026-34986?

Upgrade github.com/go-jose/go-jose/v3 to 3.0.5 or later.

Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.

Is CVE-2026-34986 being exploited?

There is no known exploitation of CVE-2026-34986 in the wild and no public exploit code.

Other vulnerabilities in go-jose

• CVE-2016-9121 Elliptic Curve Key Disclosure in go-jose Critical 9.1
• CVE-2016-9122 Go JOSE Signature Validation Bypass High 7.5
• CVE-2016-9123 Integer Overflow in go-jose High 7.5

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as ALSA-2026:10135, ALSA-2026:19173, ALSA-2026:19186, CLEANSTART-2026-AW40573, CLEANSTART-2026-EI91095, CLEANSTART-2026-FW04887 and 427 more.