CVE-2026-12817
Received Received - Intake

OpenPGP AEAD Decryption Tag Bypass in Bouncy Castle

Publication date: 2026-08-03

Last updated on: 2026-08-03

Assigner: bcorg

Description
In Bouncy Castle for Java before 1.85, OpenPGP AEAD decryption skips final tag on chunk-aligned data. This issue also affects Bouncy Castle for Java LTS before 2.73.12, and Bouncy Castle for Java FIPS (BC-FJA) before bcpg-fips 1.0.13 (1.0.X series), 2.0.13 (2.0.X series) and 2.1.13 (2.1.X series).

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Meta Information

Published
2026-08-03
Last Modified
2026-08-03
Generated
2026-08-03
AI Q&A
2026-08-03
EPSS Evaluated
N/A
NVD
CVE-2026-12817
EUVD
EUVD-2026-52136

Affected Vendors & Products

Showing 5 associated CPEs
Vendor Product Version / Range
bouncy_castle bouncy_castle to 1.85 (exc)
bouncy_castle bouncy_castle_lts to 2.73.12 (exc)
bouncy_castle bcpg_fips to 1.0.13 (exc)
bouncy_castle bcpg_fips to 2.0.13 (exc)
bouncy_castle bcpg_fips to 2.1.13 (exc)

Helpful Resources

Exploitability

CWE
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KEV
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CWE ID Description
CWE-354 The product does not validate or incorrectly validates the integrity check values or "checksums" of a message. This may prevent it from detecting if the data has been modified or corrupted in transmission.

Attack-Flow Graph

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Executive Summary

This vulnerability in Bouncy Castle for Java versions before 1.85, OpenPGP AEAD decryption skips the final tag on chunk-aligned data. This means the decryption process may not properly verify the integrity of the last data chunk, potentially allowing corrupted or tampered data to be processed without detection.

Detection Guidance

This vulnerability affects Bouncy Castle's OpenPGP AEAD decryption in specific versions. Detection requires checking installed versions of Bouncy Castle libraries. Use commands like 'mvn dependency:tree' for Java projects or inspect package managers for installed versions. Compare against affected versions: Bouncy Castle before 1.85, LTS before 2.73.12, or BC-FJA before 1.0.13, 2.0.13, 2.1.13.

Impact Analysis

This vulnerability could allow attackers to bypass integrity checks during decryption, leading to the processing of maliciously altered data. This might result in unauthorized access to sensitive information or execution of unintended operations if the affected software relies on OpenPGP for secure communications or data storage.

Compliance Impact

This vulnerability could compromise data integrity, potentially violating requirements for secure data handling in GDPR and HIPAA. Organizations using affected Bouncy Castle versions may fail to meet encryption and integrity standards, risking non-compliance and legal penalties.

Mitigation Strategies

Upgrade Bouncy Castle for Java to version 1.85 or later. For LTS versions, upgrade to 2.73.12 or later. For BC-FJA, upgrade to bcpg-fips 1.0.13, 2.0.13, or 2.1.13 depending on your series.

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