bouncycastle: BC-JAVA: private key leakage via non-constant time comparisons

A flaw was found in Legion of the Bouncy Castle Inc. BC-JAVA core. A covert timing channel vulnerability, caused by non-constant time comparisons, risks the leakage of private keys in the FrodoKEM implementation. An unauthenticated, remote attacker can potentially exploit this timing discrepancy ...

bouncycastle: BC-JAVA: private key leakage via non-constant time comparisons

A flaw was found in Legion of the Bouncy Castle Inc. BC-JAVA core. A covert timing channel vulnerability, caused by non-constant time comparisons, risks the leakage of private keys in the FrodoKEM implementation. An unauthenticated, remote attacker can potentially exploit this timing discrepancy ...

bouncycastle: BC-JAVA: private key leakage via non-constant time comparisons

A flaw was found in Legion of the Bouncy Castle Inc. BC-JAVA core. A covert timing channel vulnerability, caused by non-constant time comparisons, risks the leakage of private keys in the FrodoKEM implementation. An unauthenticated, remote attacker can potentially exploit this timing discrepancy ...

Missing Authorization

Overview Affected versions of this package are vulnerable to Missing Authorization via the post rewrite endpoint. An attacker can gain unauthorized access to the content of threads in private channels and direct messages by sending a crafted request. Remediation Upgrade...

Missing Authorization

Overview github.com/mattermost/mattermost/server/channels/app is a private-cloud Slack alternative Affected versions of this package are vulnerable to Missing Authorization via the post rewrite endpoint. An attacker can gain unauthorized access to the content of threads in private channels and...

Incorrect Authorization

Overview Affected versions of this package are vulnerable to Incorrect Authorization via the membership sync process. An attacker can remove users from any channel, including private channels, by sending crafted membership sync messages from a remote cluster that is not authorized to access the...

Incorrect Authorization

Overview github.com/mattermost/mattermost/server/channels/app is a private-cloud Slack alternative Affected versions of this package are vulnerable to Incorrect Authorization via the membership sync process. An attacker can remove users from any channel, including private channels, by sending...

Mattermost doesn't verify channel membership when processing AI-assisted message rewrites

Mattermost versions 11.5.x = 11.5.1 fail to verify channel membership when processing AI-assisted message rewrites which allows an authenticated attacker to read the content of threads in private channels and direct messages they do not have access to via a crafted request to the post rewrite...

GHSA-8R89-8W26-CQ32 Mattermost doesn't verify channel membership when processing AI-assisted message rewrites

Mattermost versions 11.5.x = 11.5.1 fail to verify channel membership when processing AI-assisted message rewrites which allows an authenticated attacker to read the content of threads in private channels and direct messages they do not have access to via a crafted request to the post rewrite...

GHSA-8H9W-W78C-VVR3 Mattermost does not verify remote cluster channel access when processing shared channel membership removals

Mattermost versions 11.5.x = 11.5.1, 10.11.x = 10.11.13, 11.4.x = 11.4.3 fail to validate that a remote cluster has access to a channel before processing membership removal requests during shared channel membership sync, which allows a malicious remote cluster to remove any user from any channel,...

CVE-2026-5163

Mattermost versions 11.5.x = 11.5.1 fail to verify channel membership when processing AI-assisted message rewrites which allows an authenticated attacker to read the content of threads in private channels and direct messages they do not have access to via a crafted request to the post rewrite...

CVE-2026-28759

Mattermost versions 11.5.x = 11.5.1, 10.11.x = 10.11.13, 11.4.x = 11.4.3 fail to validate that a remote cluster has access to a channel before processing membership removal requests during shared channel membership sync, which allows a malicious remote cluster to remove any user from any channel,...

CVE-2026-5163

Mattermost versions 11.5.x = 11.5.1 fail to verify channel membership when processing AI-assisted message rewrites which allows an authenticated attacker to read the content of threads in private channels and direct messages they do not have access to via a crafted request to the post rewrite...

CVE-2026-5163

Mattermost 11.5.x prior to 11.5.2 (up to 11.5.1 affected) fails to verify channel membership when processing AI-assisted message rewrites, allowing an authenticated user to read content from threads in private channels and direct messages they should not access via a crafted request to the post r...

CVE-2026-5163 Missing authorization check in AI message rewrite endpoint allows access to private thread content

Mattermost versions 11.5.x = 11.5.1 fail to verify channel membership when processing AI-assisted message rewrites which allows an authenticated attacker to read the content of threads in private channels and direct messages they do not have access to via a crafted request to the post rewrite...

CVE-2026-5163 Missing authorization check in AI message rewrite endpoint allows access to private thread content

Mattermost versions 11.5.x = 11.5.1 fail to verify channel membership when processing AI-assisted message rewrites which allows an authenticated attacker to read the content of threads in private channels and direct messages they do not have access to via a crafted request to the post rewrite...

EUVD-2026-30753

Mattermost versions 11.5.x = 11.5.1 fail to verify channel membership when processing AI-assisted message rewrites which allows an authenticated attacker to read the content of threads in private channels and direct messages they do not have access to via a crafted request to the post rewrite...

CVE-2026-5163 Missing authorization check in AI message rewrite endpoint allows access to private thread content

Mattermost versions 11.5.x = 11.5.1 fail to verify channel membership when processing AI-assisted message rewrites which allows an authenticated attacker to read the content of threads in private channels and direct messages they do not have access to via a crafted request to the post rewrite...

CVE-2026-28759

Mattermost versions 11.5.x = 11.5.1, 10.11.x = 10.11.13, 11.4.x = 11.4.3 fail to validate that a remote cluster has access to a channel before processing membership removal requests during shared channel membership sync, which allows a malicious remote cluster to remove any user from any channel,...

CVE-2026-28759 Insufficient authorization in shared channel membership sync allows remote cluster to remove users from arbitrary channels

Mattermost versions 11.5.x = 11.5.1, 10.11.x = 10.11.13, 11.4.x = 11.4.3 fail to validate that a remote cluster has access to a channel before processing membership removal requests during shared channel membership sync, which allows a malicious remote cluster to remove any user from any channel,...