CVE-2026-59997
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedinternal-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.
In the news
Third-party coverageSurfaced from public web coverage — external links open in a new tab.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · moderate confidenceOpenSSH's internal-sftp subsystem (sshd internal SFTP server) only parses and recognizes the first 9 command-line arguments passed to it. Any security-relevant arguments specified in position 10 or later are silently ignored, potentially leaving SFTP connections with unintended or weaker security configurations than administrators specified.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data< 10.4CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- Low
- Privileges
- None
- User interaction
- Required
- Scope
- Unchanged
- Confidentiality
- Low
- Integrity
- Low
- Availability
- None
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
-
Check OpenSSH versionRun 'sshd -V' or 'ssh -V' to determine the installed OpenSSH versionAffected if Version is below 10.4 (e.g., 10.3, 10.2, etc.)
-
Identify SFTP subsystem configurationInspect /etc/ssh/sshd_config for 'Subsystem sftp' directive - look for 'internal-sftp' as the handlerAffected if The configuration uses 'internal-sftp' rather than an external sftp-server binary path
-
Count sftp-server argumentsExtract the full argument line from the Subsystem sftp directive in sshd_config and count the total arguments after 'internal-sftp'Affected if 10 or more arguments are specified after 'internal-sftp' in the subsystem directive, meaning arguments at position 10 or later are ignored on vulnerable versions
-
Verify argument positioningReview the sshd_config sftp subsystem line and note which security-relevant options (such as -u, -l, -R, or chroot settings) appear at argument positions 10 or beyondAffected if Critical security arguments (like umask, log level, or chroot configuration) are placed at position 10 or higher in the argument list
A system is affected if it runs OpenSSH version below 10.4, uses the internal-sftp subsystem, and passes 10 or more arguments where security-critical options may be silently ignored.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
dbcve · scoped10.4
Upgrade to OpenSSH 10.4 or later where this argument-parsing limit is fixed. Until then, ensure any security-critical sftp-server arguments are positioned within the first 9 arguments, or consider using an explicit external sftp-server binary with known configuration.
OpenSSH 10.4
- Upgrade OpenSSH to version 10.4 or later
- Verify the upgrade by checking the OpenSSH version: sshd -V or ssh -V
- Test SFTP functionality to ensure internal-sftp properly handles all command-line arguments after the upgrade
- If using internal-sftp with ForceCommand or chroot configurations, verify that all intended security arguments (such as -u umask, -l, or other options) are now being properly recognized and applied
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation2.0 h
- Implementation2.0 h
- Testing2.0 h
- Review / QA1.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $1,984.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-59997 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2026-59997 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.
A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.
- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
- No weaponised exploit code, or anything meant to cause harm
- No spam, self-promotion, credentials, or personal data