CVE-2026-12852

CVE-2026-12852 is a high-severity vulnerability with a CVSS 4.0 base score of 8.7. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-789.

Key facts

Description

In Bouncy Castle for Java before 1.85, MLS wire decoder allocates attacker-declared opaque length before bounds check.

Frequently asked questions

What is CVE-2026-12852?
In Bouncy Castle for Java before 1.85, MLS wire decoder allocates attacker-declared opaque length before bounds check.
How severe is CVE-2026-12852?
CVE-2026-12852 has a CVSS 4.0 base score of 8.7, rated high severity.
Is CVE-2026-12852 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (18th percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2026-12852?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2026-12852 published?
CVE-2026-12852 was published on 2026-08-03 and last updated on 2026-08-04.

References

Other CWE-789 vulnerabilities

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