Amazon Linux 2023 Security Advisory: ALAS2023-2026-3130
Advisory Released Date: 2026-09-29
Advisory Updated Date: 2026-09-29
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. (CVE-2026-53938)
OpenIDC/cjose is a C library implementing the Javascript Object Signing and Encryption (JOSE). In versions 0.6.1 through 0.6.2.5, when cjose encrypts a JWE using an AES-CBC-HMAC content-encryption algorithm (`A128CBC-HS256`, `A192CBC-HS384`, or `A256CBC-HS512`) together with any key-management algorithm that generates a fresh content-encryption key (CEK), the CEK is all zero bytes instead of being randomly generated. The resulting JWE is therefore encrypted and authenticated under a fixed, publicly known key, so anyone who obtains the JWE can recover the plaintext and forge or modify the content. This is fixed in version 0.6.2.6 by `_cjose_jwe_set_cek_aes_cbc()` generating the CEK from `RAND_bytes`. A regression test asserts that the `encrypted_key` differs across two encryptions for each AES-CBC-HMAC variant. Until upgrading, for data encrypted with cjose, three options are available. Use an AES-GCM `enc` (`A128GCM` / `A192GCM` / `A256GCM`) instead of an AES-CBC-HMAC `enc`, use `alg=dir` with a caller-supplied CEK, or avoid using cjose for JWE encryption with the affected algorithm pair. These are mitigations for new ciphertexts only; data already encrypted under the zero key remains compromised and should be re-encrypted (and any secrets it contained rotated). (CVE-2026-53939)
Affected Packages:
cjose
Issue Correction:
Run dnf update cjose --releasever 2023.12.20260928 or dnf update --advisory ALAS2023-2026-3130 --releasever 2023.12.20260928 to update your system.
More information on how to update your system can be found on this page: Amazon Linux 2023 documentation
aarch64:
cjose-debuginfo-0.6.2.2-7.amzn2023.aarch64
cjose-0.6.2.2-7.amzn2023.aarch64
cjose-devel-0.6.2.2-7.amzn2023.aarch64
cjose-debugsource-0.6.2.2-7.amzn2023.aarch64
src:
cjose-0.6.2.2-7.amzn2023.src
x86_64:
cjose-debuginfo-0.6.2.2-7.amzn2023.x86_64
cjose-debugsource-0.6.2.2-7.amzn2023.x86_64
cjose-devel-0.6.2.2-7.amzn2023.x86_64
cjose-0.6.2.2-7.amzn2023.x86_64