Security feed

24 October 2026

advisoryOfficial CVE List24 Oct 2026

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

Russh is a Rust SSH client and server library. Prior to 0.63.1, client_read_authenticated in russh/src/client/encrypted.rs forwards CHANNEL_DATA, CHANNEL_EXTENDED_DATA, CHANNEL_EOF, CHANNEL_CLOSE, CHANNEL_OPEN_FAILURE, CHANNEL_SUCCESS, CHANNEL_FAILURE, and CHANNEL_REQUEST subtypes exit-status, exit-signal, and xon-xoff to public client::Handler callbacks without confirming that the ChannelId belongs to a channel the client opened and established. A malicious SSH server can send lifecycle events for predicted, unopened, unconfirmed, or released channel identifiers, causing application panics or corrupting command completion and exit-code tracking. This issue is fixed in version 0.63.1.

russh CVE-2026-102823

Structured advisory · Revision 1Original source

Evidence and details

Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.

Security context

Source reference: cve:CVE-2026-102823

russh

Source reference: /containers/cna/affected/0/product

Affected versions: Not stated in this record
Fixed versions: Not stated in this record
Prerequisites: Not stated in this record

Related CVEs: CVE-2026-102823
Source reference: /cveMetadata/cveId

Publisher severity

high

Source reference: /containers/cna/metrics

Event: #7897 · Revision 1
Added to Heist Feed: Sat, 24 Oct 2026 22:52:21 GMT
Publisher date: Tue, 29 Sep 2026 18:25:58 GMT

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advisoryOfficial CVE List24 Oct 2026

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

Russh is a Rust SSH client and server library. Prior to 0.63.0, the hybrid ML-KEM 768 and X25519 implementation in russh/src/kex/hybrid_mlkem.rs accepts an all-zero 32-byte peer X25519 public key in both server_dh and compute_shared_secret, forcing the X25519 contribution to the combined shared secret to zero. A malicious SSH peer can therefore make the combined secret depend only on ML-KEM, defeating the hybrid exchange's intended fallback protection if ML-KEM is later weakened. This issue is fixed in version 0.63.0.

russh CVE-2026-102824

Structured advisory · Revision 1Original source

Evidence and details

Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.

Security context

Source reference: cve:CVE-2026-102824

russh

Source reference: /containers/cna/affected/0/product

Affected versions: Not stated in this record
Fixed versions: Not stated in this record
Prerequisites: Not stated in this record

Related CVEs: CVE-2026-102824
Source reference: /cveMetadata/cveId

Publisher severity

medium

Source reference: /containers/cna/metrics

Event: #4943 · Revision 1
Added to Heist Feed: Sat, 24 Oct 2026 22:00:41 GMT
Publisher date: Tue, 29 Sep 2026 18:27:41 GMT

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advisoryOfficial CVE List24 Oct 2026

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

pageant provides a [PageantStream] type that implements [AsyncRead] and [AsyncWrite] traits and can be used to talk to a running Pageant instance. Prior to pageant 0.2.3, the Windows pageant crate's pageant/src/wmmessage.rs MemoryMap::read function trusts a peer-controlled u32 response length supplied through the 8192-byte Pageant shared-memory mapping reached by AgentClient::connect_pageant. A local process that impersonates the Pageant window can make query_pageant_direct allocate up to approximately 4 GiB and copy beyond the mapped view, reliably crashing a russh client and conditionally exposing adjacent committed memory. This issue is fixed in pageant 0.2.3.

russh pageant CVE-2026-102820

Structured advisory · Revision 1Original source

Evidence and details

Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.

Security context

Source reference: cve:CVE-2026-102820

russh

Source reference: /containers/cna/affected/0/product

Affected versions: Not stated in this record
Fixed versions: Not stated in this record
Prerequisites: Not stated in this record

pageant

Source reference: /containers/cna/affected/1/product

Affected versions: Not stated in this record
Fixed versions: Not stated in this record
Prerequisites: Not stated in this record

Related CVEs: CVE-2026-102820
Source reference: /cveMetadata/cveId

Publisher severity

medium

Source reference: /containers/cna/metrics

Event: #4893 · Revision 1
Added to Heist Feed: Sat, 24 Oct 2026 21:59:18 GMT
Publisher date: Tue, 29 Sep 2026 18:18:43 GMT

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advisoryOfficial CVE List24 Oct 2026

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

Russh is a Rust SSH client and server library. Prior to 0.63.2, an authenticated remote peer can send SSH_MSG_KEXINIT without the required SSH_MSG_KEX_ECDH_INIT and then flood SSH_MSG_CHANNEL_OPEN messages while SessionKexState::InProgress prevents priority_receiver in russh/src/server/session.rs from being drained. The server continues processing network input and enqueues a ChannelOpenReply for each request on an unbounded channel, allowing one connection to grow memory until the process is terminated. This issue is fixed in version 0.63.2.

russh CVE-2026-102821

Structured advisory · Revision 1Original source

Evidence and details

Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.

Security context

Source reference: cve:CVE-2026-102821

russh

Source reference: /containers/cna/affected/0/product

Affected versions: Not stated in this record
Fixed versions: Not stated in this record
Prerequisites: Not stated in this record

Related CVEs: CVE-2026-102821
Source reference: /cveMetadata/cveId

Publisher severity

medium

Source reference: /containers/cna/metrics

Event: #4843 · Revision 1
Added to Heist Feed: Sat, 24 Oct 2026 21:58:48 GMT
Publisher date: Tue, 29 Sep 2026 18:21:21 GMT

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advisoryOfficial CVE List24 Oct 2026

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

Russh is a Rust SSH client and server library. Prior to 0.62.6, the USERAUTH_REQUEST path reached from server::run_stream in russh/src/server/encrypted.rs increments self.common.auth_attempts but never compares it with server::Config.max_auth_attempts. An unauthenticated remote client can continue submitting authentication requests on one connection beyond the configured cap, bypassing the deployment's attempt-limiting policy and increasing online guessing opportunity and backend authentication workload. This issue is fixed in version 0.62.6.

russh CVE-2026-102825

Structured advisory · Revision 1Original source

Evidence and details

Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.

Security context

Source reference: cve:CVE-2026-102825

russh

Source reference: /containers/cna/affected/0/product

Affected versions: Not stated in this record
Fixed versions: Not stated in this record
Prerequisites: Not stated in this record

Related CVEs: CVE-2026-102825
Source reference: /cveMetadata/cveId

Publisher severity

low

Source reference: /containers/cna/metrics

Event: #4831 · Revision 1
Added to Heist Feed: Sat, 24 Oct 2026 21:58:41 GMT
Publisher date: Tue, 29 Sep 2026 18:31:32 GMT

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advisoryOfficial CVE List24 Oct 2026

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

Russh is a Rust SSH client and server library. Prior to 0.63.1, a connection configured to permit mac=none can negotiate it with a MAC-requiring CTR or CBC block cipher because the selection logic validates needs_mac() only when MAC selection fails. A remote peer can then send a packet with a decrypted length of zero, causing russh/src/cipher/mod.rs to shrink the previously read block before indexing buffer.buffer[16..], which panics and terminates the connection task. This issue is fixed in version 0.63.1.

russh CVE-2026-102822

Structured advisory · Revision 1Original source

Evidence and details

Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.

Security context

Source reference: cve:CVE-2026-102822

russh

Source reference: /containers/cna/affected/0/product

Affected versions: Not stated in this record
Fixed versions: Not stated in this record
Prerequisites: Not stated in this record

Related CVEs: CVE-2026-102822
Source reference: /cveMetadata/cveId

Publisher severity

low

Source reference: /containers/cna/metrics

Event: #3996 · Revision 1
Added to Heist Feed: Sat, 24 Oct 2026 21:44:46 GMT
Publisher date: Tue, 29 Sep 2026 18:23:28 GMT

Read the original announcement