OpenIDC cjose 0.6.2.2 JWE Decryption cjose_jwe_import/cjose_jwe_decrypt encrypted_key heap-based overflow

Summaryinfo

A vulnerability labeled as critical has been found in OpenIDC cjose. Affected by this vulnerability is the function cjose_jwe_import/cjose_jwe_decrypt of the component JWE Decryption. Such manipulation of the argument encrypted_key leads to heap-based overflow. This vulnerability is listed as CVE-2026-53938. The attack may be performed from remote. There is no available exploit. The affected component should be upgraded.

Detailsinfo

A vulnerability was found in OpenIDC cjose and classified as critical. Affected by this issue is the function cjose_jwe_import/cjose_jwe_decrypt of the component JWE Decryption. The manipulation of the argument encrypted_key with an unknown input leads to a heap-based overflow vulnerability. Using CWE to declare the problem leads to CWE-122. A heap overflow condition is a buffer overflow, where the buffer that can be overwritten is allocated in the heap portion of memory, generally meaning that the buffer was allocated using a routine such as malloc(). Impacted is confidentiality, integrity, and availability. CVE summarizes:

OpenIDC/cjose is a C library implementing the Javascript Object Signing and Encryption (JOSE). Prior to version 0.6.2.5, cjose's JWE decryption path for the AES Key Wrap key-management algorithms (`alg` = `A128KW`, `A192KW`, `A256KW`) does not validate the length of the attacker-supplied `encrypted_key` (JWE Encrypted Key) before unwrapping it into a fixed-size, heap-allocated Content Encryption Key (CEK) buffer. A remote, unauthenticated attacker who can submit a crafted JWE to an application that decrypts it with an AES-KW symmetric key can trigger an out-of-bounds heap write, corrupting the heap. This leads at minimum to a crash (denial of service) and, depending on the heap layout and allocator, may be leverageable for further memory-corruption impact. `cjose_jwe_import()` / `cjose_jwe_decrypt()` are pre-authentication entry points: they parse and process fully attacker-controlled input. Upgrade to cjose 0.6.2.5 to receive a patch. If upgrading is not immediately possible, reject the AES Key Wrap algorithms (`A128KW`/`A192KW`/`A256KW`) for untrusted JWEs at the application layer.

The advisory is shared for download at github.com. This vulnerability is handled as CVE-2026-53938 since 06/11/2026. The exploitation is known to be easy. The attack may be launched remotely. No form of authentication is required for exploitation. There are known technical details, but no exploit is available.

Upgrading to version 0.6.2.5 eliminates this vulnerability.

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Productinfo

Vendor

• OpenIDC

Name

• cjose

Version

• 0.6.2.2

Website

• Product: https://github.com/OpenIDC/cjose/

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