Integrity-Verification Downgrade Vulnerability in Apache Camel PGP

Apache Camel’s camel-crypto-pgp component is vulnerable to an integrity-verification downgrade (CVE-2026-85243). The unmarshal() process only enforces modification detection checks when messages use OpenPGP symmetrically encrypted integrity-protected data packets. Messages utilizing older symmetrically encrypted data packets skip this integrity check entirely. Because the packet type is determined by the message producer, an attacker or a man-in-the-middle can choose to send legacy packets to bypass integrity validation. This allows the decryption of malleable ciphertext that would otherwise be rejected, potentially leading to unauthorized data processing. This issue affects versions from 4.0.0 before 4.18.5, and 4.19.0 before 4.22.1. The fix introduces a requireIntegrityProtection option, which defaults to true and enforces the use of protected packets.

Impact

Successful exploitation allows for the decryption of unauthenticated and potentially modified PGP-encrypted messages. This impact is significant in environments relying on Camel for secure data ingestion, as it circumvents the fundamental guarantee that decrypted content has not been tampered with in transit. Organizations across sectors utilizing Apache Camel for PGP data processing are at risk if they communicate with untrusted or compromised external entities that can influence message packet selection.

Recommendation

• Upgrade Apache Camel to versions 4.18.5, 4.22.1, or 4.23.0 to leverage the new requireIntegrityProtection security option.
• If immediate patching is not possible, implement a pre-processing check to inspect incoming OpenPGP packet headers and reject any message that does not utilize the integrity-protected data packet format before it reaches the unmarshal() function.
• Review existing Camel routes using camel-crypto-pgp to ensure that requireIntegrityProtection is set to true and evaluate if incoming traffic can be limited to trusted sources that strictly use modern PGP packet types.