CVE intelligence and bounded remediation

CVE-2026-10303 — In ServerCo getssl version 2.49 and prior, the ACME challenge token returned to the client was not strictly validated against RFC 8555...

High CVSS 7.4

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.

Severity
High
CVSS
7.4 (3.1)
Published
2026-06-16
CISA KEV
Not currently listed
Ecosystem
software/application
Weaknesses
CWE-73

Affected products

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Matched remediation archetype

Path traversal, unsafe upload, and file handling

This catalog composition supplies bounded fallback guidance. Explicitly reviewed curated workflows load with the complete record below.

Check exposure

  • Trace untrusted filenames, archive entries, URLs, and path segments into read, write, include, extraction, and upload operations.
  • Identify filesystem roots, mount permissions, symbolic-link behavior, archive handling, and whether uploaded content is web-accessible or executable.
  • Review canonicalization and containment checks across supported operating systems and storage backends.

Remediate safely

  • Generate server-side storage identifiers and resolve paths beneath a fixed root using filesystem-aware containment checks.
  • Reject absolute, parent-relative, alternate-separator, device, link, and archive entries that escape the intended root.
  • Store uploads outside executable or served paths, validate type and size, and use private atomic temporary files.

Authoritative sources

Complete CVE record and remediation plan

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