Bouncy Castle LTS native GCM chunking can cause bad-tag exception on decryption
In Bouncy Castle LTS for Java, the AES/GCM native implementation used on Intel CPUs with AES PAA instruction sets (AVX / VAES / VAESF variants) can intermittently produce an incorrect authentication tag verification result during decryption when the ciphertext is fed in via a mix of `update()` calls followed by `doFinal()`. It is possible to work around it by either using `doFinal()` only (as the BCJSSE does) or by configuring the module to run in pure Java mode, by setting the system property "org.bouncycastle.native.cpu_variant" to java.
describes (1)
Related CVEs.
| ID | severity | exploitable | ||
|---|---|---|---|---|
| CVE-2026-8149US | — | — | ||
A vulnerability in Legion of the Bouncy Castle Inc. BC-LTS bcprov-lts8on on X86_64, AVX, AVX-512f, Linux, Legion of the Bouncy Castle Inc. BC-FJA bc-fips on Linux, X86_64, AVX, AVX… | ||||
references
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