Incorrect Authorization

Overview Affected versions of this package are vulnerable to Incorrect Authorization in org.bouncycastle.mls.protocol.Group.validateExternalCachedProposals through external MLS commit Remove proposal validation. An attacker can evict an arbitrary group member and take over that slot in the ratche...

Incorrect Authorization

Overview Affected versions of this package are vulnerable to Incorrect Authorization in org.bouncycastle.mls.protocol.Group.validateExternalCachedProposals through external MLS commit Remove proposal validation. An attacker can evict an arbitrary group member and take over that slot in the ratche...

UBUNTU-CVE-2026-71890

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 d...

CVE-2026-71890

Bouncy Castle for Java versions before 1.86 are vulnerable to an authorization flaw in the MLS (RFC 9420) protocol implementation. The org.bouncycastle.mls.protocol.Group.validateExternalCachedProposals method fails to verify that a Remove proposal in an external commit belongs to the joiner. Thi...

EUVD-2026-92006

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 d...

CVE-2026-71890 MLS external commit can remove an arbitrary group member

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 d...

CVE-2026-71890 MLS external commit can remove an arbitrary group member

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 d...

CVE-2026-71890 MLS external commit can remove an arbitrary group member

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 d...

PT-2026-104569

Name of the Vulnerable Software and Affected Versions Bouncy Castle for Java versions prior to 1.86 Description Validation of an MLS RFC 9420 external commit's proposal list in the validateExternalCachedProposals function of org.bouncycastle.mls.protocol.Group failed to verify that a removed leaf...