CVE-2026-10303

HIGH

MEDIUM Priority: 0.06 BB Relevance: 65/100

Published: 2026-06-16 Modified: 2026-10-25 First seen: 2026-10-29 Status: active

Attack Surface

Network No Auth No Interaction Conf. Impact Integ. Impact

CVSS Vector Breakdown

AV: Network

AC: High

PR: None

UI: None

S: Unchanged

C: High

I: High

A: None

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.