CVE-2026-39827

🔶 medium

Summary

An authenticated SSH client that repeatedly opened channels which were rejected by the server caused unbounded memory growth, eventually crashing the server process and affecting all connected users. Rejected channels are now properly removed from the connection's internal state and released for garbage collection.

CVSS Score

6.5

Medium

EPSS Score

0.3

Exploit Probability

Published Date

2026-05-22

First Seen: 2026-05-23

📊 Relative Risk Intelligence

This CVE is Lower Risk - more severe than 46.6% of all 365,863 vulnerabilities in our database.

#195,492

Below average severity

Severity Percentile

🎯 CISA SSVC Assessment Updated: May 22, 2026

🔍 Exploitation Status

None

No known exploits

⚙️ Automatable

Requires human interaction

💥 Technical Impact

Partial

Limited system impact

🏆 Discovered By

Ziyan Zhou

SSVC data provided by CISA

Last Modified 2026-07-23

Source NVD 🔗

CVSS Vector 3.1 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

CWE IDs (Weakness Types)

CWE-924

📦 Affected Products 1

Vendor	Product	Status	Affected Versions
golang	crypto	Affected	< 0.52.0

🔗 References 4

https://go.dev/cl/781320

Issue Tracking

https://go.dev/issue/35127

Issue Tracking

https://groups.google.com/g/golang-announce/c/a082jn...

Mailing List

https://pkg.go.dev/vuln/GO-2026-5016

Vendor Advisory

🔗 Related CVEs 6

CVE ID	Severity	CVSS	EPSS	Summary	Published
CVE-2026-56855	⚠️ high	7.5	0.4	Previously, after a channel has been established, a malicious peer could send crafted messages that would deadlock the e...	2026-09-02
CVE-2026-78662	⚠️ high	7.5	0.3	Previously, a channel registered in the mux's chanList is not usable until it is established. A malicious peer was able ...	2026-09-02
CVE-2026-39828	🔶 medium	6.3	0.4	When an SSH server authentication callback returned PartialSuccessError with non-nil Permissions, those permissions were...	2026-05-22
CVE-2026-39829	⚠️ high	7.5	0.5	The RSA and DSA public key parsers did not enforce size limits on key parameters. A crafted public key with an excessive...	2026-05-22
CVE-2026-39830	⛔ critical	9.1	0.6	A malicious SSH peer could send unsolicited global request responses to fill an internal buffer, blocking the connection...	2026-05-22
CVE-2026-39831	⛔ critical	9.1	0.4	The Verify() method for FIDO/U2F security key types (sk-ecdsa-sha2-nistp256@openssh.com, sk-ssh-ed25519@openssh.com) did...	2026-05-22

These CVEs affect the same products