In Bouncy Castle for Java before 1.85, DTLS handshake reassembler allocates buffer from unchecked 24-bit length. (CVE-2026-59646)
Description
A vulnerability in Bouncy Castle for Java before version 1.85 allows the DTLS handshake reassembler to allocate a buffer using an unchecked 24-bit length. This flaw also affects Bouncy Castle for Java LTS versions before 2.73.12 and Bouncy Castle for Java FIPS versions before bctls-fips 1.0.24, 2.0.24, and 2.1.24. The issue can lead to a denial of service due to improper resource allocation.
CVSS v3.1
Score 7.5high
Affected software
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
CVE-2026-59646 describes a vulnerability in Bouncy Castle for Java where the DTLS handshake reassembler allocates buffers based on an unchecked 24-bit length value. This can cause excessive memory allocation leading to denial of service (CWE-789). The affected versions include Bouncy Castle for Java prior to 1.85, Bouncy Castle for Java LTS prior to 2.73.12, and Bouncy Castle for Java FIPS before bctls-fips 1.0.24, 2.0.24, and 2.1.24. The CVSS v3.1 score is 7.5 (high severity) with network attack vector, low attack complexity, no privileges or user interaction required, and impacts availability only.
Potential Impact
The vulnerability can be exploited remotely without authentication or user interaction to cause a denial of service by exhausting system resources through unchecked buffer allocation during DTLS handshake processing. There is no impact on confidentiality or integrity.
Mitigation Recommendations
No explicit patch links or vendor advisory were provided. Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until a fix is confirmed, users should consider mitigating exposure by limiting access to DTLS services or applying any vendor-recommended temporary mitigations if available.
Technical Details
- Gcve Source
- db.gcve.eu
- Osv Id
- GHSA-4m8h-6737-hrw6
- Osv Schema Version
- 1.4.0
- Aliases
- ["CVE-2026-59646"]
- Database Specific Severity
- HIGH
- Cvss Version
- 3.1
- State
- PUBLISHED
Threat ID: 6a92f816acd9273b49e90ec3
Added to database: 08/29/2026, 15:17:42 UTC
Last enriched: 09/08/2026, 01:37:23 UTC
Last updated: 10/13/2026, 18:48:21 UTC
Views: 72
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