CVE-2026-102825

A flaw was found in russh. The server fails to enforce the configured limit on maximum authentication attempts during user authentication. An unauthenticated remote attacker can exploit this flaw by continuously submitting authentication requests over a single connection. This allows an attacker ...

russh: russh: State corruption via unverified SSH channel identifiers

A flaw was found in russh, a Secure Shell SSH client and server library. When communicating with a client, a malicious SSH server can send channel lifecycle events referencing unverified, unopened, or closed channel identifiers. Because the library forwards these events to client handlers without...

russh: russh: Cryptographic fallback bypass via missing public key validation

A flaw was found in russh. The library fails to validate peer public keys during hybrid cryptographic key exchange, accepting an all-zero key. A remote attacker acting as a malicious Secure Shell SSH peer can exploit this flaw during connection negotiation to force the classical encryption...

russh: russh: Authentication attempt limit bypass via unenforced maximum authentication attempts

A flaw was found in russh. The server fails to enforce the configured limit on maximum authentication attempts during user authentication. An unauthenticated remote attacker can exploit this flaw by continuously submitting authentication requests over a single connection. This allows an attacker ...

russh: russh: Denial of Service via unbounded memory exhaustion during stalled key renegotiation

A flaw was found in russh. An authenticated remote attacker can cause a Denial of Service DoS by initiating a Secure Shell SSH key renegotiation without completing it and flooding the server with channel open requests. Because the server continues buffering incoming requests without draining the...

EUVD-2026-89203

pageant: Out-of-bounds read / oversized allocation in pageant MemoryMap::read via a malicious Pageant agent Windows...

pageant: Out-of-bounds read / oversized allocation in `pageant` MemoryMap::read via a malicious Pageant agent (Windows)

Summary MemoryMap::read in the pageant crate part of the russh workspace, used by russh's SSH-agent client on Windows via AgentClient::connectpageant copies a peer-controlled number of bytes out of an 8192-byte shared-memory view with no bounds check — unlike the sibling MemoryMap::write, which...

EUVD-2026-89204

Russh: Unbounded memory exhaustion via CHANNELOPEN flood during a client-stalled rekey...

Russh: Unbounded memory exhaustion via CHANNEL_OPEN flood during a client-stalled rekey

Summary A russh server can be driven to unbounded heap growth process OOM / kill by a peer that speaks only standard SSH messages, in the default configuration. The peer starts a key re-exchange sends SSHMSGKEXINIT but never sends the follow-up SSHMSGKEXECDHINIT, leaving the server's kex state...

russh: negotiating a MAC-requiring block cipher (CTR/CBC) with mac=none causes a slice-index-out-of-range panic

Summary SshBlockCipher implementations AES-CBC, AES-CTR, 3DES-CBC, etc. report needsmac == true, meaning they are documented/intended to always be paired with a separate integrity MAC. However, key-exchange negotiation only checks needsmac inside the fallback branch of MAC algorithm selection use...

EUVD-2026-89205

russh: negotiating a MAC-requiring block cipher CTR/CBC with mac=none causes a slice-index-out-of-range panic...

EUVD-2026-89206

russh: Client-side channel-scoped Handler callbacks fire for channel IDs the client never opened...

GHSA-47HW-GVQ5-R2GM russh: Client-side channel-scoped Handler callbacks fire for channel IDs the client never opened

Summary CVE-2026-68930 was fixed by adding Session::isestablishedchannel in russh/src/server/encrypted.rs, which gates every channel-scoped SERVER-side message CHANNELREQUEST, CHANNELDATA, CHANNELEOF, CHANNELCLOSE, CHANNELWINDOWADJUST, CHANNELEXTENDEDDATA on enc.channels.get&channel.issomeand|c|...

russh: Client-side channel-scoped Handler callbacks fire for channel IDs the client never opened

Summary CVE-2026-68930 was fixed by adding Session::isestablishedchannel in russh/src/server/encrypted.rs, which gates every channel-scoped SERVER-side message CHANNELREQUEST, CHANNELDATA, CHANNELEOF, CHANNELCLOSE, CHANNELWINDOWADJUST, CHANNELEXTENDEDDATA on enc.channels.get&channel.issomeand|c|...

GHSA-W3JG-PJXF-73P4 Russh: Missing X25519 zero-point validation in hybrid ML-KEM key exchange

Vulnerability The hybrid ML-KEM 768 + X25519 key exchange implementation in russh/src/kex/hybridmlkem.rs does not validate that the remote peer's X25519 public key is not the zero point all-zero 32-byte value. This allows a remote peer to force the X25519 contribution to the combined shared secre...

EUVD-2026-89207

Russh: Missing X25519 zero-point validation in hybrid ML-KEM key exchange...

Russh: Missing X25519 zero-point validation in hybrid ML-KEM key exchange

Vulnerability The hybrid ML-KEM 768 + X25519 key exchange implementation in russh/src/kex/hybridmlkem.rs does not validate that the remote peer's X25519 public key is not the zero point all-zero 32-byte value. This allows a remote peer to force the X25519 contribution to the combined shared secre...

EUVD-2026-89365

Russh: Configured server auth-attempt cap is not enforced in the USERAUTHREQUEST runtime path...

Russh: Configured server auth-attempt cap is not enforced in the USERAUTH_REQUEST runtime path

Details Affected versions and vulnerable location - Confirmed present on default branch main at HEAD 0089c89c94753bebbec12b956c07a1cd38740379. - Crate version at HEAD: 0.62.4. - Vulnerable locations on current default branch: - russh/src/server/mod.rs:91 pub maxauthattempts: usize -...

CVE-2026-102822

A flaw was found in russh. This vulnerability allows a remote attacker to cause a Denial of Service DoS by terminating active connection tasks. When a connection is configured to permit sessions without a Message Authentication Code MAC, improper algorithm negotiation allows pairing with block...