Upstream information

CVE-2026-71890 at MITRE

Description

In Bouncy Castle for Java before 1.86, validation of an MLS (RFC 9420) external commit's proposal list, org.bouncycastle.mls.protocol.Group.validateExternalCachedProposals, counted the proposals by type and bounded the removed leaf index but never established that the removed leaf had anything to do with the joiner. RFC 9420 sec. 12.2 permits at most one Remove proposal in an external commit, with which the joiner removes an old version of themselves, and requires that where one is present the LeafNode in the commit's path field meet the criteria it would have to meet in an Update for the removed leaf, in particular that its credential present identifiers acceptable for the removed participant. The ordinary proposal-list validator's self-remove rule is deliberately not applied on this path, because a resync commit legitimately removes a leaf the joiner owns, but nothing was put in its place. Any party holding the group's public GroupInfo, which is precisely what an external joiner is meant to be given, could therefore commit a Remove naming any member's LeafIndex and have every member apply it, evicting that member and taking over their slot in the ratchet tree. The credential check that should have prevented this existed only in the gRPC interop harness and so protected no other caller of the public Group.externalJoin and Group.handle API. An external commit carrying a Remove is now accepted only when the removed leaf's credential is identical to the one in the joiner's own new leaf, on both the sending and the receiving side.

SUSE information

Overall state of this security issue: Pending

This issue is currently rated as having moderate severity.

CVSS v3 Scores
CVSS detail SUSE
Base Score 5.9
Vector CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N
Attack Vector Network
Attack Complexity High
Privileges Required None
User Interaction None
Scope Unchanged
Confidentiality Impact None
Integrity Impact High
Availability Impact None
CVSSv3 Version 3.1
CVSS v4 Scores
CVSS detail CNA (91579145-5d7b-4cc5-b925-a0262ff19630) SUSE
Base Score 8.7 8.2
Vector CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:Amber CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N
Attack Vector Network Network
Attack Complexity Low Low
Attack Requirements None Present
Privileges Required None None
User Interaction None None
Vulnerable System Confidentiality Impact None None
Vulnerable System Integrity Impact High High
Vulnerable System Availability Impact None None
Subsequent System Confidentiality Impact None None
Subsequent System Integrity Impact None None
Subsequent System Availability Impact None None
CVSSv4 Version 4.0 4.0
SUSE Bugzilla entry: 1284219 [IN_PROGRESS]

No SUSE Security Announcements cross referenced.

List of packages in QA

Product(s) Package(s)
SUSE Linux Enterprise High Performance Computing 15 SP4-ESPOS
  • bouncycastle >= 1.86-150200.3.41.1
  • bouncycastle-pg >= 1.86-150200.3.41.1
  • bouncycastle-pkix >= 1.86-150200.3.41.1
  • bouncycastle-util >= 1.86-150200.3.41.1
SUSE Linux Enterprise High Performance Computing 15 SP4-LTSS
  • bouncycastle >= 1.86-150200.3.41.1
  • bouncycastle-pg >= 1.86-150200.3.41.1
  • bouncycastle-pkix >= 1.86-150200.3.41.1
  • bouncycastle-util >= 1.86-150200.3.41.1
SUSE Linux Enterprise High Performance Computing 15 SP5-ESPOS
  • bouncycastle >= 1.86-150200.3.41.1
  • bouncycastle-pg >= 1.86-150200.3.41.1
  • bouncycastle-pkix >= 1.86-150200.3.41.1
  • bouncycastle-util >= 1.86-150200.3.41.1
SUSE Linux Enterprise High Performance Computing 15 SP5-LTSS
  • bouncycastle >= 1.86-150200.3.41.1
  • bouncycastle-pg >= 1.86-150200.3.41.1
  • bouncycastle-pkix >= 1.86-150200.3.41.1
  • bouncycastle-util >= 1.86-150200.3.41.1
SUSE Linux Enterprise Module for Development Tools 15 SP7
  • bouncycastle >= 1.86-150200.3.41.1
  • bouncycastle-pg >= 1.86-150200.3.41.1
  • bouncycastle-pkix >= 1.86-150200.3.41.1
  • bouncycastle-util >= 1.86-150200.3.41.1
SUSE Linux Enterprise Server 15 SP7
  • bouncycastle >= 1.86-150200.3.41.1
  • bouncycastle-pg >= 1.86-150200.3.41.1
  • bouncycastle-pkix >= 1.86-150200.3.41.1
  • bouncycastle-util >= 1.86-150200.3.41.1
SUSE Linux Enterprise Desktop 15 SP7
  • bouncycastle >= 1.86-150200.3.41.1
  • bouncycastle-pg >= 1.86-150200.3.41.1
  • bouncycastle-pkix >= 1.86-150200.3.41.1
  • bouncycastle-util >= 1.86-150200.3.41.1
SUSE Linux Enterprise Server for SAP Applications 15 SP7
  • bouncycastle >= 1.86-150200.3.41.1
  • bouncycastle-pg >= 1.86-150200.3.41.1
  • bouncycastle-pkix >= 1.86-150200.3.41.1
  • bouncycastle-util >= 1.86-150200.3.41.1
SUSE Linux Enterprise Server 15 SP4-LTSS
  • bouncycastle >= 1.86-150200.3.41.1
  • bouncycastle-pg >= 1.86-150200.3.41.1
  • bouncycastle-pkix >= 1.86-150200.3.41.1
  • bouncycastle-util >= 1.86-150200.3.41.1
SUSE Linux Enterprise Server 15 SP4-LTSS
  • bouncycastle >= 1.86-150200.3.41.1
  • bouncycastle-pg >= 1.86-150200.3.41.1
  • bouncycastle-pkix >= 1.86-150200.3.41.1
  • bouncycastle-util >= 1.86-150200.3.41.1
SUSE Linux Enterprise Server 15 SP5-LTSS
  • bouncycastle >= 1.86-150200.3.41.1
  • bouncycastle-pg >= 1.86-150200.3.41.1
  • bouncycastle-pkix >= 1.86-150200.3.41.1
  • bouncycastle-util >= 1.86-150200.3.41.1
SUSE Linux Enterprise Server 15 SP5-LTSS
  • bouncycastle >= 1.86-150200.3.41.1
  • bouncycastle-pg >= 1.86-150200.3.41.1
  • bouncycastle-pkix >= 1.86-150200.3.41.1
  • bouncycastle-util >= 1.86-150200.3.41.1
SUSE Linux Enterprise Server 15 SP6-LTSS
  • bouncycastle >= 1.86-150200.3.41.1
  • bouncycastle-pg >= 1.86-150200.3.41.1
  • bouncycastle-pkix >= 1.86-150200.3.41.1
  • bouncycastle-util >= 1.86-150200.3.41.1
SUSE Linux Enterprise Server 15 SP6-LTSS
  • bouncycastle >= 1.86-150200.3.41.1
  • bouncycastle-pg >= 1.86-150200.3.41.1
  • bouncycastle-pkix >= 1.86-150200.3.41.1
  • bouncycastle-util >= 1.86-150200.3.41.1
SUSE Linux Enterprise Server for SAP Applications 15 SP4
  • bouncycastle >= 1.86-150200.3.41.1
  • bouncycastle-pg >= 1.86-150200.3.41.1
  • bouncycastle-pkix >= 1.86-150200.3.41.1
  • bouncycastle-util >= 1.86-150200.3.41.1
SUSE Linux Enterprise Server for SAP Applications 15 SP5
  • bouncycastle >= 1.86-150200.3.41.1
  • bouncycastle-pg >= 1.86-150200.3.41.1
  • bouncycastle-pkix >= 1.86-150200.3.41.1
  • bouncycastle-util >= 1.86-150200.3.41.1
SUSE Linux Enterprise Server for SAP Applications 15 SP6
  • bouncycastle >= 1.86-150200.3.41.1
  • bouncycastle-pg >= 1.86-150200.3.41.1
  • bouncycastle-pkix >= 1.86-150200.3.41.1
  • bouncycastle-util >= 1.86-150200.3.41.1

Status of this issue by product and package

Please note that this evaluation state might be work in progress, incomplete or outdated. Also information for service packs in the LTSS phase is only included for issues meeting the LTSS criteria. If in doubt, feel free to contact us for clarification. The updates are grouped by state of their lifecycle. SUSE product lifecycles are documented on the lifecycle page.

Product(s) Source package State
Products under general support and receiving all security fixes.
SUSE Linux Enterprise Desktop 15 SP7 bouncycastle In progress
SUSE Linux Enterprise Module for Development Tools 15 SP7 bouncycastle In progress
SUSE Linux Enterprise Server 15 SP7 bouncycastle In progress
SUSE Linux Enterprise Server 16.0 bouncycastle Affected
SUSE Linux Enterprise Server 16.1 bouncycastle Affected
SUSE Linux Enterprise Server for SAP Applications 15 SP7 bouncycastle In progress
SUSE Linux Enterprise Server for SAP applications 16.0 bouncycastle Affected
SUSE Linux Enterprise Server for SAP applications 16.1 bouncycastle Affected
openSUSE Leap 16.0 bouncycastle Affected
Products under Long Term Service Pack support and receiving important and critical security fixes.
SUSE Linux Enterprise High Performance Computing 15 SP4-LTSS bouncycastle In progress
SUSE Linux Enterprise High Performance Computing 15 SP5 bouncycastle Affected
SUSE Linux Enterprise High Performance Computing 15 SP5-LTSS bouncycastle In progress
SUSE Linux Enterprise Module for Development Tools 15 SP4 bouncycastle Affected
SUSE Linux Enterprise Module for Development Tools 15 SP5 bouncycastle Affected
SUSE Linux Enterprise Module for Development Tools 15 SP6 bouncycastle Affected
SUSE Linux Enterprise Server 15 SP4 bouncycastle Affected
SUSE Linux Enterprise Server 15 SP4-LTSS bouncycastle In progress
SUSE Linux Enterprise Server 15 SP5 bouncycastle Affected
SUSE Linux Enterprise Server 15 SP5-LTSS bouncycastle In progress
SUSE Linux Enterprise Server 15 SP6 bouncycastle Affected
SUSE Linux Enterprise Server 15 SP6-LTSS bouncycastle In progress
SUSE Linux Enterprise Server for SAP Applications 15 SP4 bouncycastle In progress
SUSE Linux Enterprise Server for SAP Applications 15 SP5 bouncycastle In progress
SUSE Linux Enterprise Server for SAP Applications 15 SP6 bouncycastle In progress
Products past their end of life and not receiving proactive updates anymore.
SUSE Enterprise Storage 7 bouncycastle Affected
SUSE Enterprise Storage 7.1 bouncycastle Affected
SUSE Linux Enterprise Desktop 15 SP2 bouncycastle Affected
SUSE Linux Enterprise Desktop 15 SP3 bouncycastle Affected
SUSE Linux Enterprise Desktop 15 SP4 bouncycastle Affected
SUSE Linux Enterprise Desktop 15 SP5 bouncycastle Affected
SUSE Linux Enterprise Desktop 15 SP6 bouncycastle Affected
SUSE Linux Enterprise High Performance Computing 15 SP2 bouncycastle Affected
SUSE Linux Enterprise High Performance Computing 15 SP2-ESPOS bouncycastle Affected
SUSE Linux Enterprise High Performance Computing 15 SP2-LTSS bouncycastle Affected
SUSE Linux Enterprise High Performance Computing 15 SP3 bouncycastle Affected
SUSE Linux Enterprise High Performance Computing 15 SP3-ESPOS bouncycastle Affected
SUSE Linux Enterprise High Performance Computing 15 SP3-LTSS bouncycastle Affected
SUSE Linux Enterprise High Performance Computing 15 SP4 bouncycastle Affected
SUSE Linux Enterprise High Performance Computing 15 SP4-ESPOS bouncycastle In progress
SUSE Linux Enterprise High Performance Computing 15 SP5-ESPOS bouncycastle In progress
SUSE Linux Enterprise Module for Development Tools 15 SP2 bouncycastle Affected
SUSE Linux Enterprise Module for Development Tools 15 SP3 bouncycastle Affected
SUSE Linux Enterprise Real Time 15 SP2 bouncycastle Affected
SUSE Linux Enterprise Real Time 15 SP3 bouncycastle Affected
SUSE Linux Enterprise Real Time 15 SP4 bouncycastle Affected
SUSE Linux Enterprise Server 15 SP2 bouncycastle Affected
SUSE Linux Enterprise Server 15 SP2-BCL bouncycastle Affected
SUSE Linux Enterprise Server 15 SP2-LTSS bouncycastle Affected
SUSE Linux Enterprise Server 15 SP3 bouncycastle Affected
SUSE Linux Enterprise Server 15 SP3-BCL bouncycastle Affected
SUSE Linux Enterprise Server 15 SP3-LTSS bouncycastle Affected
SUSE Linux Enterprise Server for SAP Applications 15 SP2 bouncycastle Affected
SUSE Linux Enterprise Server for SAP Applications 15 SP3 bouncycastle Affected
SUSE Manager Proxy 4.1 bouncycastle Affected
SUSE Manager Proxy 4.2 bouncycastle Affected
SUSE Manager Proxy 4.3 bouncycastle Affected
SUSE Manager Retail Branch Server 4.1 bouncycastle Affected
SUSE Manager Retail Branch Server 4.2 bouncycastle Affected
SUSE Manager Retail Branch Server 4.3 bouncycastle Affected
SUSE Manager Server 4.1 bouncycastle Affected
SUSE Manager Server 4.2 bouncycastle Affected
SUSE Manager Server 4.3 bouncycastle Affected
openSUSE Leap 15.3 bouncycastle Affected
openSUSE Leap 15.4 bouncycastle Affected
openSUSE Leap 15.5 bouncycastle Affected
openSUSE Leap 15.6 bouncycastle Affected
Products at an unknown state of their lifecycle.
SUSE Linux Enterprise Server 16.2 bouncycastle Analysis
SUSE Linux Enterprise Server for NVIDIA 16.1 bouncycastle Affected
Container Status
containers/apache-pulsar:3.3 bouncycastleAffected

SUSE Timeline for this CVE

CVE page created: Mon Oct 5 16:44:23 2026
CVE page last modified: Fri Oct 9 15:50:09 2026