CVE-2026-102821

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Source
https://cve.org/CVERecord?id=CVE-2026-102821
Import Source
https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-102821.json
JSON Data
https://api.osv.dev/v1/vulns/CVE-2026-102821
Aliases
Downstream
CGA (2)
DEBIAN (1)
RHSA (1)
UBUNTU (1)
Published
2026-09-29T18:21:21Z
Modified
2026-10-21T02:54:29Z
Severity
  • 6.5 (Medium) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H CVSS Calculator
Summary
Russh: Unbounded memory exhaustion via CHANNEL_OPEN flood during a client-stalled rekey
Details

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.

Database specific 
{
    "cna_assigner":  "GitHub_M",
    "cwe_ids":  [
        "CWE-400",
        "CWE-770"
    ],
    "osv_generated_from":  "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/102xxx/CVE-2026-102821.json"
}
References

Affected packages

Git / github.com/eugeny/russh

Affected ranges

Type
GIT
Repo
https://github.com/eugeny/russh
Events
Introduced
0 Unknown introduced commit / All previous commits are affected
Fixed
8a51a0dca4f6fbdcc3ce98c627254026b25b3252
Fixed
a282af361ac99bc76b80876d1aae128e89dbf66b
Database specific
Show details 
{
    "extracted_events":  [
        {
            "range":  [
                {
                    "introduced":  "0"
                },
                {
                    "fixed":  "0.63.2"
                }
            ],
            "source":  "AFFECTED_FIELD",
            "strategy":  "StringRangeExpression"
        },
        {
            "range":  [
                {
                    "fixed":  "a282af361ac99bc76b80876d1aae128e89dbf66b"
                }
            ],
            "source":  "REFERENCES_COMMIT"
        },
        {
            "original_tag":  "v0.63.2",
            "range":  [
                {
                    "fixed":  "8a51a0dca4f6fbdcc3ce98c627254026b25b3252"
                }
            ],
            "source":  "REFERENCES_TAG"
        }
    ]
}

Affected versions

0.*
0.37.0-beta.1
v0.*
v0.34.0
v0.35.0-beta.1
v0.35.0-beta.2
v0.35.0-beta.3
v0.35.0-beta.5
v0.35.0-beta.6
v0.35.0-beta.7
v0.35.0-beta.8
v0.35.0-beta.9
v0.36.1
v0.37.0
v0.37.0-beta.1
v0.37.1
v0.38.0
v0.38.0-beta.1
v0.39.0-beta.1
v0.40.0
v0.40.1
v0.40.2
v0.42.0
v0.43.0
v0.43.0-beta.1
v0.44.0
v0.44.0-beta.1
v0.44.0-beta.3
v0.44.0-beta.4
v0.45.0
v0.46.0
v0.47.0-beta.3
v0.47.0-beta.4
v0.48.0
v0.48.1
v0.48.2
v0.49.0
v0.50.0
v0.50.0-beta.10
v0.50.0-beta.11
v0.50.0-beta.12
v0.50.0-beta.2
v0.50.0-beta.3
v0.50.0-beta.4
v0.50.0-beta.5
v0.50.0-beta.6
v0.50.0-beta.7
v0.50.0-beta.8
v0.50.0-beta.9
v0.50.1
v0.50.3
v0.50.4
v0.51.0
v0.51.0-beta.1
v0.51.0-beta.2
v0.51.0-beta.3
v0.51.1
v0.52.0
v0.52.0-beta.1
v0.52.1
v0.53.0
v0.53.0-beta.1
v0.54.0
v0.54.1
v0.54.2
v0.54.3
v0.54.4
v0.54.5
v0.54.6
v0.55.0
v0.56.0
v0.57.0
v0.57.1
v0.58.0
v0.59.0
v0.60.0
v0.60.1
v0.60.2
v0.60.3
v0.61.0
v0.61.1
v0.61.2
v0.62.0
v0.62.1
v0.62.2
v0.62.3
v0.62.4
v0.62.5
v0.62.6
v0.62.7
v0.63.0
v0.63.0-beta.1
v0.63.1

Database specific

source 
"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-102821.json"