Bouncycastle: In Bouncy Castle for Java before 1.85, OpenPGP user-attribute subpacket length bounded only by JVM max memory. (CVE-2026-59649)
Description
Bouncy Castle for Java versions before 1.85 have a vulnerability in the OpenPGP user-attribute subpacket length handling, where the length is only bounded by the JVM maximum memory. This issue also affects certain LTS and FIPS versions prior to specified patch releases. The vulnerability can lead to denial of service due to resource exhaustion. The CVSS score is 7.5, indicating a medium severity impact primarily affecting availability.
CVSS v3.1
Score 7.5high
Affected software
pkg:deb/ubuntu/bouncycastle?arch=source&distro=esm-apps/xenialpkg:deb/ubuntu/bouncycastle?arch=source&distro=esm-apps/bionicpkg:deb/ubuntu/bouncycastle?arch=source&distro=esm-apps/focalpkg:deb/ubuntu/bouncycastle?arch=source&distro=esm-apps/jammypkg:deb/ubuntu/bouncycastle?arch=source&distro=esm-apps/noblepkg:deb/ubuntu/bouncycastle?arch=source&distro=stonkingpkg:deb/ubuntu/bouncycastle?arch=source&distro=resoluteRun on your own infrastructure? Check whether these packages are installed with threat-finder — our free open-source scanner.
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
In Bouncy Castle for Java versions prior to 1.85, the OpenPGP user-attribute subpacket length is not properly bounded except by the maximum memory available to the JVM. This can allow an attacker to craft a user-attribute subpacket with an excessively large length, potentially causing resource exhaustion and denial of service. The issue also affects Bouncy Castle for Java LTS versions before 2.73.12 and Bouncy Castle for Java FIPS versions before bcpg-fips 1.0.13 (1.0.X series), 2.0.13 (2.0.X series), and 2.1.13 (2.1.X series). The vulnerability is tracked as CVE-2026-59649 and has a CVSS v3.1 score of 7.5 (AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H).
Potential Impact
The vulnerability can cause denial of service by allowing an attacker to specify an excessively large user-attribute subpacket length in OpenPGP data, which is only bounded by the JVM's maximum memory. This can lead to resource exhaustion and application unavailability. There is no impact on confidentiality or integrity reported.
Mitigation Recommendations
The vulnerability affects versions before 1.85 and certain LTS and FIPS versions prior to their respective patch releases. Users should upgrade to Bouncy Castle for Java version 1.85 or later, Bouncy Castle for Java LTS version 2.73.12 or later, and Bouncy Castle for Java FIPS versions bcpg-fips 1.0.13, 2.0.13, or 2.1.13 and later. Patch status is not explicitly confirmed in the provided data, but the version numbers indicate fixed versions. Users should consult the vendor advisory for official patch availability and upgrade guidance.
Technical Details
- Gcve Source
- db.gcve.eu
- Osv Id
- UBUNTU-CVE-2026-59649
- Osv Schema Version
- 1.7.0
- Ecosystems
- ["Ubuntu:Pro:16.04:LTS","Ubuntu:Pro:18.04:LTS","Ubuntu:Pro:20.04:LTS","Ubuntu:Pro:22.04:LTS","Ubuntu:Pro:24.04:LTS","Ubuntu:26.10","Ubuntu:26.04:LTS"]
- Cvss Version
- 3.1
- State
- PUBLISHED
Threat ID: 6ad3f5d82cdf04f65666324a
Added to database: 10/17/2026, 22:25:28 UTC
Last enriched: 10/18/2026, 00:30:09 UTC
Last updated: 10/18/2026, 00:30:09 UTC
Views: 2
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