Is CVE-2026-71883 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-71883 being exploited in the wild.

How severe is CVE-2026-71883?

Informational severity, published 3 October 2026.

Which products and versions are affected?

Bouncycastle Bouncy Castle For Java Lts before 2.73.13 (affected from 2.73.4).

Is there a fix for CVE-2026-71883?

Yes: fixed in Bouncy Castle for Java LTS 2.73.13. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

How is CVE-2026-71883 attacked?

It is attacked with local access, in a software library.

Am I affected by CVE-2026-71883?

Check whether you run Bouncycastle Bouncy Castle For Java Lts at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-71883: Bouncy Castle Java LTS native AES cipher key disclosure on array aliasing

CVE-2026-71883 · Severity: info · Published 2026-10-03

Bouncy Castle for Java LTS, a widely-used cryptography library, contains a bug in its native implementations of AES encryption that causes encryption-in-place operations to overwrite ciphertext with the raw encryption key. Applications that encrypt data directly into their own key array instead of a separate output buffer will accidentally expose the encryption key in place of the encrypted message, potentially transmitting or storing sensitive key material.

Technologies: Bouncycastle Bouncy Castle For Java Lts. Vendors: Bouncycastle.

Quick answers

Is CVE-2026-71883 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-71883 being exploited in the wild.
How severe is CVE-2026-71883?: Informational severity, published 3 October 2026.
Which products and versions are affected?: Bouncycastle Bouncy Castle For Java Lts before 2.73.13 (affected from 2.73.4).
Is there a fix for CVE-2026-71883?: Yes: fixed in Bouncy Castle for Java LTS 2.73.13. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-71883 attacked?: It is attacked with local access, in a software library.
Am I affected by CVE-2026-71883?: Check whether you run Bouncycastle Bouncy Castle For Java Lts at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

How to fix

Fixed in: Bouncy Castle for Java LTS 2.73.13

Technical details

The native packet ciphers for AES-CBC, CCM, CFB, CTR, GCM and GCM-SIV in Bouncy Castle Java LTS (versions 2.73.4 through 2.73.12) use JNI to perform encryption but incorrectly release input arrays (including keys and IVs) in read-write mode, allowing stale copies to overwrite the output buffer. When an application passes the same Java array as both input and output—such as encrypting directly into a KeyParameter.getKey() array—the output buffer is committed first, then the unchanged key bytes are committed over the ciphertext. The pure-Java implementations and streaming native modes are unaffected, as are regular Bouncy Castle distributions without native code.

Affected products

Bouncycastle Bouncy Castle for Java LTS before 2.73.13 (affected from 2.73.4)

Timeline

2026-10-03: disclosed

References

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