CVE-2026-39830: A malicious SSH peer could send unsolicited global request responses to fill an internal buffer, blocking the

Q: How do I fix CVE-2026-39830?

crypto: upgrade to 0.52.0. Exact commands for each OS are on this page.

Q: Is CVE-2026-39830 being exploited?

CVE-2026-39830 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2026-39830 affect?

CVE-2026-39830 affects crypto. Severity is critical (CVSS 9.1). A malicious SSH peer could send unsolicited global request responses to fill an internal buffer, blocking the connection's read loop. The blocked goroutine could not be released by calling Close(), resulting in a resource leak per connectio

Q: How urgent is CVE-2026-39830?

Priority 50/100. Critical severity; Remotely exploitable, no login, no user action

This month

CRITICAL 9.1REMOTEUPGRADE

CVE-2026-39830 is a critical-severity flaw (CVSS 9.1) affecting crypto. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

A malicious SSH peer could send unsolicited global request responses to fill an internal buffer, blocking the connection's read loop. The blocked goroutine could not be released by calling Close(), resulting in a resource leak per connection. Unsolicited global responses are now discarded.

Why this priority

Critical severity
Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	9.1 (Critical)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.7% (top 48%)
CISA exploited list	No
Weakness	CWE-119, CWE-772
Published	2026-05-22
Last modified	2026-09-16

Publisher (CNA): Go Project · Vendor: golang

Last updated 2026-09-16 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-05-22 04:16 UTCPublished CVE record published
2026-09-16 13:17 UTCUpdated Record last modified

golang crypto UPGRADE

Affected: < 0.52.0

Fixed in: 0.52.0

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy crypto || rpm -q crypto || crypto --version

2. UPGRADE to 0.52.0 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade crypto

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade crypto

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-39830?

crypto: upgrade to 0.52.0. Exact commands for each OS are on this page.

Is CVE-2026-39830 being exploited?

CVE-2026-39830 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-39830 affect?

CVE-2026-39830 affects crypto. Severity is critical (CVSS 9.1). A malicious SSH peer could send unsolicited global request responses to fill an internal buffer, blocking the connection's read loop. The blocked goroutine could not be released by calling Close(), resulting in a resource leak per connectio

How urgent is CVE-2026-39830?

Priority 50/100. Critical severity; Remotely exploitable, no login, no user action

Software pages

Go (Golang) vulnerabilities

Related CVEs

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References

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