In Bouncy Castle for Java before 1.85, OpenPGP AEAD decryption skips final tag on chunk-aligned data. (CVE-2026-12817)
Bouncy Castle for Java versions before 1.85 have a vulnerability in OpenPGP AEAD decryption where the final authentication tag is skipped on chunk-aligned data. This flaw also affects Bouncy Castle for Java LTS before 2.73.12 and Bouncy Castle for Java FIPS versions prior to bcpg-fips 1.0.13, 2.0.13, and 2.1.13 in their respective series. The issue can lead to improper verification of encrypted data integrity.
AI Analysis
Technical Summary
The vulnerability CVE-2026-12817 affects Bouncy Castle for Java's OpenPGP AEAD decryption implementation. Specifically, when processing chunk-aligned data, the final authentication tag is skipped, potentially allowing integrity verification to be bypassed. This impacts multiple Bouncy Castle Java variants including the mainline, LTS, and FIPS versions prior to the specified fixed releases. The vulnerability is categorized under CWE-354 (Improper Validation of Integrity Check Value).
Potential Impact
The skipping of the final authentication tag during AEAD decryption can result in failure to detect tampering or corruption of encrypted data. This undermines the cryptographic integrity guarantees of OpenPGP messages processed by affected Bouncy Castle versions, potentially allowing attackers to manipulate ciphertext without detection.
Mitigation Recommendations
No explicit patch or remediation details are provided in the input data. Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Users should monitor official Bouncy Castle advisories for updates and apply any released fixes for versions prior to 1.85 (mainline), 2.73.12 (LTS), and the specified FIPS versions (bcpg-fips 1.0.13, 2.0.13, 2.1.13).
In Bouncy Castle for Java before 1.85, OpenPGP AEAD decryption skips final tag on chunk-aligned data. (CVE-2026-12817)
Description
Bouncy Castle for Java versions before 1.85 have a vulnerability in OpenPGP AEAD decryption where the final authentication tag is skipped on chunk-aligned data. This flaw also affects Bouncy Castle for Java LTS before 2.73.12 and Bouncy Castle for Java FIPS versions prior to bcpg-fips 1.0.13, 2.0.13, and 2.1.13 in their respective series. The issue can lead to improper verification of encrypted data integrity.
CVSS v4.0
Affected software
pkg:maven/org.bouncycastle/bcprov-jdk15onpkg:maven/org.bouncycastle/bcprov-jdk15on-ltspkg:maven/org.bouncycastle/bcpg-fipsRun on your own infrastructure? Check whether these packages are installed with threat-finder — our free open-source scanner.
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The vulnerability CVE-2026-12817 affects Bouncy Castle for Java's OpenPGP AEAD decryption implementation. Specifically, when processing chunk-aligned data, the final authentication tag is skipped, potentially allowing integrity verification to be bypassed. This impacts multiple Bouncy Castle Java variants including the mainline, LTS, and FIPS versions prior to the specified fixed releases. The vulnerability is categorized under CWE-354 (Improper Validation of Integrity Check Value).
Potential Impact
The skipping of the final authentication tag during AEAD decryption can result in failure to detect tampering or corruption of encrypted data. This undermines the cryptographic integrity guarantees of OpenPGP messages processed by affected Bouncy Castle versions, potentially allowing attackers to manipulate ciphertext without detection.
Mitigation Recommendations
No explicit patch or remediation details are provided in the input data. Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Users should monitor official Bouncy Castle advisories for updates and apply any released fixes for versions prior to 1.85 (mainline), 2.73.12 (LTS), and the specified FIPS versions (bcpg-fips 1.0.13, 2.0.13, 2.1.13).
Technical Details
- Gcve Source
- db.gcve.eu
- Osv Id
- GHSA-9q38-7pr7-8j6w
- Osv Schema Version
- 1.4.0
- Aliases
- ["CVE-2026-12817"]
- Ecosystems
- []
- Database Specific Severity
- HIGH
- Cvss Version
- 4.0
Threat ID: 6a710680bf32cb7a34396f67
Added to database: 08/03/2026, 21:22:08 UTC
Last enriched: 08/03/2026, 21:40:52 UTC
Last updated: 08/04/2026, 03:17:46 UTC
Views: 3
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