Disclosure summary
In Bouncy Castle for Java before 1.86, a truncated OpenPGP encrypted message was accepted with no error reported, and on the SEIPD version 1 path with no integrity check performed at all. RFC 9580 sec. 13.7 permits an implementation to release the cleartext of the fully authenticated chunks when streaming but requires it to indicate a clear error as soon as the truncation is detected, and to report suspect integrity when it discovers malleable ciphertext. The truncation was detected and then discarded: when a message is truncated but the length field of the enclosing packet is left unchanged, BCPGInputStream.PartialInputStream raises an EOFException for the missing ciphertext, and BCPGInputStream.nextPacketTag() reports an EOFException as a clean end of message, so the packet stream above it stopped as though no packets remained. On the AEAD path (SEIPD version 2 and the version 5 AEAD packet), when the literal data packet ended on an AEAD chunk boundary and the consumer read in increments smaller than one chunk, the look-ahead for the packet after the literal triggered the truncated chunk read, so BcAEADUtil and JceAEADUtil never reached the trailing message tag of sec. 5.13.2 that authenticates the total plaintext length; the caller received the plaintext of the fully authenticated chunks, every packet following the literal was silently dropped, and no exception was raised, so a signed and encrypted message read back as a well-formed unsigned one. Every byte released on that path remained individually authenticated, making this a missing truncation error rather than a forgery, and it is a residual of CVE-2026-12817, which closed the same outcome for an attacker who corrects the outer packet length. On the SEIPD version 1 path the consequence was more serious: Integrit
Source-reported weakness categories
CWE-345, CWE-354
Source-specific records & product guidance
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NIST National Vulnerability Database · NVD-CVE-2026-85515
Open original source · Updated Oct 06, 2026
Only CPE matches marked vulnerable=true are indexed. AND/OR platform conditions must be checked in the original NVD record.
Original records & references
PUBLISHED 2026-10-03T05:17:06-04:00
MODIFIED 2026-10-06T10:49:40-04:00
INGESTED 2026-10-06T11:45:30-04:00