Vulnerability · Published Sep 4, 2026 · Assigned by CPANSec

CVE-2026-82309Robots::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

Medium 4.3

In plain English

A medium-severity resource allocation without limits in Robots-Validate. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 31% of all known vulnerabilities).

Severity (CVSS 3.1)4.3Medium

Exploit odds (30 days)0.4%top 68.6% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official description

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.

Affected products (as reported)

Vendor	Product	Versions
	Robots-Validate	0.3.2 – before 0.3.11

Weakness: CWE-770, CWE-405 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N

In plain English

Official description

Affected products (as reported)

References