Source: rust-russh X-Debbugs-CC: [email protected] Severity: grave Tags: security
Hi, The following vulnerabilities were published for rust-russh. CVE-2026-102820[0]: | 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. https://github.com/Eugeny/russh/security/advisories/GHSA-g4mp-vgx3-xrvm Fixed by: https://github.com/Eugeny/russh/commit/5d566989ebabfdebfe6b33243d31765a0812260b (v0.63.2) CVE-2026-102821[1]: | 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. https://github.com/Eugeny/russh/security/advisories/GHSA-35g8-35p8-c8fw Fixed by: https://github.com/Eugeny/russh/commit/a282af361ac99bc76b80876d1aae128e89dbf66b (v0.63.2) CVE-2026-102822[2]: | 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. https://github.com/Eugeny/russh/security/advisories/GHSA-p8qx-h547-fjw9 Fixed by: https://github.com/Eugeny/russh/commit/2885385abfee279092a41d80c6cb6ac367353159 (v0.63.1) CVE-2026-102823[3]: | 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. https://github.com/Eugeny/russh/security/advisories/GHSA-47hw-gvq5-r2gm Fixed by: https://github.com/Eugeny/russh/commit/3430fd26ecafc0dc3705210f5f39a9119fa22774 (v0.63.1) CVE-2026-102824[4]: | 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. https://github.com/Eugeny/russh/security/advisories/GHSA-w3jg-pjxf-73p4 Fixed by: https://github.com/Eugeny/russh/commit/8da8967f196472576b1565d518a0ed60fce60f0c (v0.63.0) CVE-2026-102825[5]: | 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. https://github.com/Eugeny/russh/security/advisories/GHSA-g6xm-f9xp-qq35 Fixed by: https://github.com/Eugeny/russh/commit/f8fd0b11a393364dc7f01a182482d86adafdd653 (v0.62.6) If you fix the vulnerabilities please also make sure to include the CVE (Common Vulnerabilities & Exposures) ids in your changelog entry. For further information see: [0] https://security-tracker.debian.org/tracker/CVE-2026-102820 https://www.cve.org/CVERecord?id=CVE-2026-102820 [1] https://security-tracker.debian.org/tracker/CVE-2026-102821 https://www.cve.org/CVERecord?id=CVE-2026-102821 [2] https://security-tracker.debian.org/tracker/CVE-2026-102822 https://www.cve.org/CVERecord?id=CVE-2026-102822 [3] https://security-tracker.debian.org/tracker/CVE-2026-102823 https://www.cve.org/CVERecord?id=CVE-2026-102823 [4] https://security-tracker.debian.org/tracker/CVE-2026-102824 https://www.cve.org/CVERecord?id=CVE-2026-102824 [5] https://security-tracker.debian.org/tracker/CVE-2026-102825 https://www.cve.org/CVERecord?id=CVE-2026-102825 Please adjust the affected versions in the BTS as needed.
