CVE-2026-10303 ServerCo getssl ACME shell script path injection
Attackers can exploit path traversal in getssl to write files and execute remote commands via malicious ACME challenge tokens.
- 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-2026-10303?
CVE-2026-10303 is a high-severity path traversal vulnerability in ServerCo getssl, published on 16 Jun 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
In ServerCo getssl version 2.49 and prior, the ACME challenge token returned to the client was not strictly validated against RFC 8555 before being used in challenge-file handling, allowing a maliciously crafted token to influence local path/filename usage during validation. An attacker who can supply ACME challenge responses to getssl (for example, a malicious or compromised CA endpoint, or an on-path adversary able to tamper with that response path) could exploit this to achieve unauthorized file write/path traversal effects, usually with elevated privileges, ultimately allowing for remote command injection. This issue appears related in spirit to CVE-2023-38198, and is an instance of CWE-73, "External control of file name or path." Other ACME shell script handlers may be affected by similar issues.
Weakness: CWE-73
Which versions are affected by CVE-2026-10303?
How do I fix CVE-2026-10303?
No fix has been published for CVE-2026-10303 yet. Limit exposure of the affected software until one is available.
Upgrade, and resolve every user-supplied path against an allowed base folder before opening it. More about Path traversal.
Is CVE-2026-10303 being exploited?
There is no known exploitation of CVE-2026-10303 in the wild and no public exploit code.
Sources
Also known as GHSA-9v83-jvh5-6gh3.