Vulnerability · Published Oct 11, 2026 · Assigned by VulnCheck

CVE-2026-108741Shepherd through 0.3.1 SSRF via DNS Rebinding in Citation Checker

Low 3.1

In plain English

A low-severity security flaw in Shepherd from shepherd-agents. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 8% of all known vulnerabilities).

Severity (CVSS 3.1)3.1Low

Exploit odds (30 days)0.2%top 92.2% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official description

Shepherd (shepherd-ai) through 0.3.1 contains a server-side request forgery guard bypass in the citation-checker extra because the public_url guard validates a resolved address but fetch re-resolves the hostname at connect time. Attackers who plant a crafted reference URL in a checked document and control its DNS can rebind it to internal addresses, sending GET requests to internal HTTP(S) services and capturing responses in evidence files.

Affected products (as reported)

Vendor	Product	Versions
shepherd-agents	Shepherd	0 – through 0.3.1

Weakness: CWE-367 · Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:N/A:N

References

https://hackmd.io/@haind03/shepherd-citation-checker-dns-rebinding-ssrf third-party-advisory
https://github.com/shepherd-agents/shepherd/blob/d34d5ca334871dfcb5a3dc76dd78045829fa4e56/shepherd/extras/citation-checker/src/shepherd_citation_checker/_engine/network.py#L9-L17 technical-description
https://github.com/shepherd-agents/shepherd/blob/d34d5ca334871dfcb5a3dc76dd78045829fa4e56/shepherd/extras/citation-checker/src/shepherd_citation_checker/_engine/fetch.py#L34-L55 technical-description
https://github.com/shepherd-agents/shepherd product
VulnCheck Advisory: Shepherd through 0.3.1 SSRF via DNS Rebinding in Citation Checker third-party-advisory