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CVE-2026-34986 High

Go JOSE Panics in JWE decryption

### Impact Decrypting a JSON Web Encryption (JWE) object will panic if the `alg` field indicates a key wrapping algorithm ([one ending in `KW`](https://pkg.go.dev/github.com/go-jose/go-jose/v4#pkg-constants), 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. ### Fixed In 4.1.4 and v3.0.5 ### Workarounds If the list of `keyAlgorithms` passed to `ParseEncrypted()` / `ParseEncryptedJSON()` / `ParseEncryptedCompact()` does not include key wrapping algorithms (those ending in `KW`), your application is unaffected. If your application uses key wrapping, you can prevalidate to the JWE objects to ensure the `encrypted_key` field is nonempty. If your application accepts JWE Compact Serialization, apply that validation to the corresponding field of that serialization (the data between the first and second `.`). ### Thanks Thanks to Datadog's Security team for finding this issue.

Exploit probability 0.7%
Published April 3, 2026
Required by Not available
Last source change May 26, 2026

02 / AFFECTED SOFTWARE

Affected packages

Go github.com/go-jose/go-jose/v3
Go github.com/go-jose/go-jose/v4
Go github.com/go-jose/go-jose
Go github.com/go-jose/go-jose/v3
Go github.com/go-jose/go-jose/v4
Unknown Unknown

15 explicit affected versions

03 / CONNECTIONS

Connected vulnerabilities

related OPENSUSE-SU-2026:21483-1

04 / EVIDENCE

Source records

Open Source Vulnerabilities GO-2026-4945

The go-jose package is subject to a panic when decrypting certain JSON Web Encryption (JWE) tokens. This occurs when an attacker can provide a maliciously crafted JWE token that triggers an unhandled exception during the decryption process, leading to a denial-of-service.

View original source
Open Source Vulnerabilities GHSA-78h2-9frx-2jm8

### Impact Decrypting a JSON Web Encryption (JWE) object will panic if the `alg` field indicates a key wrapping algorithm ([one ending in `KW`](https://pkg.go.dev/github.com/go-jose/go-jose/v4#pkg-constants), 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. ### Fixed In 4.1.4 and v3.0.5 ### Workarounds If the list of `keyAlgorithms` passed to `ParseEncrypted()` / `ParseEncryptedJSON()` / `ParseEncryptedCompact()` does not include key wrapping algorithms (those ending in `KW`), your application is unaffected. If your application uses key wrapping, you can prevalidate to the JWE objects to ensure the `encrypted_key` field is nonempty. If your application accepts JWE Compact Serialization, apply that validation to the corresponding field of that serialization (the data between the first and second `.`). ### Thanks Thanks to Datadog's Security team for finding this issue.

View original source
Open Source Vulnerabilities CVE-2026-34986

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.

View original source

05 / REFERENCES

Further evidence