CVE-2026-5268 SFTP Server Authentication Weakness
Remote attackers can bypass SFTP authentication to read or modify system files on Ciena network devices.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-5268?
CVE-2026-5268 is a critical authentication bypass vulnerability in CIENA 6500 S-Series, published on 6 Jul 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
An authentication bypass vulnerability exists in the default SFTP server component utilized across the Ciena products listed. This vulnerability allows a remote, unauthenticated attacker to bypass security controls and gain unauthorized access to the underlying filesystem. Successful exploitation could allow an attacker to read or modify system files.
Weakness: CWE-288
Which versions are affected by CVE-2026-5268?
How do I fix CVE-2026-5268?
No fix has been published for CVE-2026-5268 yet. Limit exposure of the affected software until one is available.
Upgrade, and rotate credentials and sessions that may have been exposed. More about Authentication bypass.
Is CVE-2026-5268 being exploited?
There is no known exploitation of CVE-2026-5268 in the wild and no public exploit code.
Sources
Also known as GHSA-m6c7-7xhp-6vhc.