CVE-2026-12802
Bouncy Castle CMS decryption fails to enforce tag-length, enabling RCE from crafted ciphertext.
Is CVE-2026-12802 being exploited?
Not confirmed. CVE-2026-12802 does not appear in CISA's Known Exploited Vulnerabilities catalog, which records only exploitation that has been observed and reported publicly. That is evidence of absence of a report, not evidence the flaw is unattacked. EPSS currently estimates a 0.15% probability of exploitation in the next 30 days.
How severe is CVE-2026-12802?
CVE-2026-12802 is rated High with a CVSS score of 8.7. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.
Is there a patch for CVE-2026-12802?
Yes. A fix has been recorded for CVE-2026-12802. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-12802 affect?
CVE-2026-12802 affects Bouncy Castle for Java < 1.85, Bouncy Castle for Java LTS < 2.73.12, Bouncy Castle for Java FIPS (bcpkix-fips) < 1.0.12 / 2.0.12 / 2.1.12. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-12802?
Upgrade to fixed Bouncy Castle releases (>=1.85, >=2.73.12 LTS, or listed FIPS fixes) and audit Java deps.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Remote code execution during CMS AuthEnvelopedData decryption via malformed tag-length; attacker can execute code when a vulnerable app processes crafted ciphertext.
Patch when possible
- affected>= 1.0.0 and < 1.0.12
- affected>= 2.0.0 and < 2.0.12
- affected>= 2.1.0 and < 2.1.12
- affected< 1.85
- affected>= 2.73.0 and < 2.73.12
As published in the CVE Program record. A version outside these ranges is not a statement that it is unaffected — vendors sometimes understate a range, and distribution-backported builds carry upstream numbers that do not reflect what was patched into them.