PatchTheCVECVE-2026-16000: Missing cryptographic step in the DSTU 7624 CCM mode implementation (KCcmBlockCipher) in Legion of the Bouncy
CVE-2026-16000 is a high-severity flaw (CVSS 7.5) affecting bc-csharp. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.
Missing cryptographic step in the DSTU 7624 CCM mode implementation (KCcmBlockCipher) in Legion of the Bouncy Castle Inc. bc-csharp before 2.7.0 allows an attacker who can observe encrypted messages of known or chosen content to forge ciphertexts with valid authentication tags, via messages encrypted without associated data. The cause is that the G1 block, which binds the nonce, the message length and the parameter flags into the CBC-MAC, was pro
Why this priority
- High severity
- Remotely exploitable, no login, no user action
A fixed release or distro patch exists.
Risk facts
| CVSS score | 7.5 (High) |
| Attack vector | Network (remote) |
| Attack complexity | Low |
| Privileges needed | None |
| User interaction | None |
| EPSS exploit chance | 0.3% (top 78%) |
| CISA exploited list | No |
| Weakness | CWE-325 |
| Published | 2026-10-02 |
| Last modified | 2026-10-27 |
Last updated 2026-10-27 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score
Am I affected?
Timeline
- Published CVE record published
- Updated Record last modified
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.
Quick answers
How do I fix CVE-2026-16000?
bc-csharp: upgrade to 2.7.0. Exact commands for each OS are on this page.
Is CVE-2026-16000 being exploited?
CVE-2026-16000 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.
What does CVE-2026-16000 affect?
CVE-2026-16000 affects bc-csharp. Severity is high (CVSS 7.5). Missing cryptographic step in the DSTU 7624 CCM mode implementation (KCcmBlockCipher) in Legion of the Bouncy Castle Inc. bc-csharp before 2.7.0 allows an attacker who can observe encrypted messages of known or chosen content to forge ciphe
How urgent is CVE-2026-16000?
Priority 37/100. High severity; Remotely exploitable, no login, no user action
Related CVEs
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