CVE-2026-82309

MediumCVSS 4.3

Published: 04/09/2026(UTC)Updated: 08/09/2026(UTC)Translated: 04/09/2026(UTC)NVD NIST

Exploitation Probability (EPSS)

Low risk

0.24%

15th percentile - higher than 15% of all known CVEs

Summary

Risk Assessment

The vulnerability can be exploited to perform DoS attacks on DNS servers or delay responses, potentially affecting the availability of services using this library.

Recommendation

Immediately update Robots::Validate to version 0.3.11 or later, which includes a fix limiting the number of DNS queries.

Other vulnerabilities in Robots::Validate

CVE-2026-112921High
A vulnerability in the Perl Robots::Validate library (versions 0.4.3 to 0.4.10) allows the state of the Aho-Corasick matcher used for User-Agent matching to persist across requests. If a User-Agent ends partway through a robot name, the next User-Agent checked by the same object can complete that name, causing misclassification of the client as a robot.

Original NVD description (English source)

Robots::Validate versions from 0.3.2 before 0.3.11 for Perl allow unbounded outbound DNS queries per validation via a forward-confirmation loop that does not bound the names it queries. _check_dns issues one PTR query for the client address, keeps the returned names matching the rule's domain, and issues a forward query for each until one resolves back to that address. Nothing bounds that list, and a client controls the reverse zone for its own address, so it chooses how many names the PTR answer holds. Net::DNS refetches a truncated answer over TCP by default, so the 512-byte UDP payload does not cap it either. Any client whose User-Agent matches a rule with a domain reaches _check_dns. Each forward name is distinct and client-chosen, so every query misses the local cache and is resolved against the authoritative servers for that domain. The queries are synchronous, so the caller is held until all of them answer or time out.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS