Bug 2543501 (CVE-2026-102821) - CVE-2026-102821 russh: russh: Denial of Service via unbounded memory exhaustion during stalled key renegotiation
Summary: CVE-2026-102821 russh: russh: Denial of Service via unbounded memory exhausti...
Keywords:
Status: NEW
Alias: CVE-2026-102821
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
medium
medium
Target Milestone: ---
Assignee: Product Security
QA Contact:
URL:
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Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2026-09-29 18:40 UTC by OSIDB Bzimport
Modified: 2026-09-29 19:01 UTC (History)
0 users

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Description OSIDB Bzimport 2026-09-29 18:40:34 UTC
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.


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