CVE-2026-12852
MLS wire decoder allocates attacker-declared opaque length before bounds check
HIGH
7.5
CVSS Score
Published: August 3, 2026 at 02:55 AM UTC
Updated: October 23, 2026 at 10:10 PM UTC
2 products affected across 2 vendorsBc JavaBC Java
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Severity
HIGH7.5
Exploit prediction
EPSS 0.5%
SSVC
No known exploit
Description
In Bouncy Castle for Java before 1.85, MLS wire decoder allocates attacker-declared opaque length before bounds check.
Affected
Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.
v < 1.85
Affected range stops below 1.85, so it looks safe — our inference, not a vendor statement
90%
1.73 ≤ v < 1.851.73
Affected range stops below 1.85, so it looks safe — our inference, not a vendor statement
Remediation
No guide yetNo remediation guidance has been written for this CVE yet. What the record does show:
References (3)
Source: cverecord
https://github.com/bcgit/bc-java/wiki/CVE-2026-12852Patch
Source: cverecord
https://github.com/bcgit/bc-java/commit/a747038bb5bbd5e29fb2b7607ab38af1fd8d1790Vendor AdvisoryThird Party Advisory
Source: cverecord
https://github.com/bcgit/bc-java/wiki/CVE%E2%80%902026%E2%80%9012852SSVC — Action Prioritization
SSVCNo known exploitAutomatablePartial impact
SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.
CVSS
- Attack Vector
- NETWORK
- Complexity
- LOW
- Privileges
- NONE
- User Interaction
- NONE
- Scope
- UNCHANGED
- Confidentiality
- NONE
- Integrity
- NONE
- Availability
- HIGH
Vector?
Quick Info
StatusANALYZED
CWE
CWE-789
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