CVE-2026-59997: internal-sftp in sshd in OpenSSH before 10.4 recognizes only the first 9 command-line arguments, which can be

Q: How do I fix CVE-2026-59997?

openssh: upgrade to 10.4. Exact commands for each OS are on this page.

Q: Is CVE-2026-59997 being exploited?

CVE-2026-59997 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-2026-59997 affect?

CVE-2026-59997 affects openssh. Severity is medium (CVSS 4.2). internal-sftp in sshd in OpenSSH before 10.4 recognizes only the first 9 command-line arguments, which can be important if a later command-line argument would have helped to ensure the intended security properties of an SFTP connection.

Q: How urgent is CVE-2026-59997?

Priority 21/100. On your watchlist

Routine

MEDIUM 4.2WATCHLISTUPGRADE

CVE-2026-59997 is a medium-severity flaw (CVSS 4.2) affecting openssh. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

internal-sftp in sshd in OpenSSH before 10.4 recognizes only the first 9 command-line arguments, which can be important if a later command-line argument would have helped to ensure the intended security properties of an SFTP connection.

Why this priority

On your watchlist

A fixed release or distro patch exists.

Risk facts

CVSS score	4.2 (Medium)
Attack vector	Network (remote)
Attack complexity	High
Privileges needed	None
User interaction	Required
EPSS exploit chance	0.2% (top 93%)
CISA exploited list	No
Weakness	CWE-1284
Published	2026-07-08
Last modified	2026-10-25

Publisher (CNA): MITRE · Vendor: openbsd

Last updated 2026-10-25 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-07-08 01:16 UTCPublished CVE record published
2026-10-25 20:10 UTCUpdated Record last modified

openbsd openssh UPGRADE

Affected: < 10.4

Fixed in: 10.4

Safe to downgrade to: no unaffected older release

1. Check installed version

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

2. UPGRADE to 10.4 (Debian / Ubuntu)

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

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade openssh

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-2026-59997?

openssh: upgrade to 10.4. Exact commands for each OS are on this page.

Is CVE-2026-59997 being exploited?

CVE-2026-59997 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-2026-59997 affect?

CVE-2026-59997 affects openssh. Severity is medium (CVSS 4.2). internal-sftp in sshd in OpenSSH before 10.4 recognizes only the first 9 command-line arguments, which can be important if a later command-line argument would have helped to ensure the intended security properties of an SFTP connection.

How urgent is CVE-2026-59997?

Priority 21/100. On your watchlist

Software pages

OpenSSH vulnerabilities

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References

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