Libssh: libssh: denial of service via zero advertised channel packet size
Published Jul 21, 2026 · Updated Oct 23, 2026
Original summary
Normalized public record · Updated Oct 23, 2026
Libssh: libssh: denial of service via zero advertised channel packet size
Publisher and source text is retained separately from QFinch interpretation.
QFinch assessment
A flaw was found in libssh. A remote authenticated peer can advertise a zero maximum packet size in SSH_MSG_CHANNEL_OPEN, causing later channel writes to loop indefinitely and consume CPU, leading to denial of service.
Evidence: public source recordsAffected products
| Affected package, product or range | Fix status |
|---|---|
| Consult the referenced vendor advisory for affected versions. | Consult source advisory |
Matching a version is only one part of assessing exposure. QFinch has not assessed your environment on this public page.
Remediation
Apply the vendor-supported fixed release or mitigation, then verify the affected component is no longer reachable.
- Confirm the affected product and reachable code path exist in your environment.
- Apply the vendor-supported patch or mitigation from the primary advisory.
- Rescan the exact deployed revision and retain verification evidence.
Evidence coverage
- SSVC priority
- LOW
- Confidence
- Not available
- Aliases
- None reported
Scores appear only when corresponding evidence exists. Missing data is never interpreted as zero risk.
Sources and record history
- RHSA-2026:42922 ↗
- RHSA-2026:55855 ↗
- RHSA-2026:62217 ↗
- RHSA-2026:62218 ↗
- access.redhat.com ↗
- RHBZ#2498176 ↗
Record history
Published Jul 21, 2026 · Last refreshed Oct 23, 2026