Pi-hole FTL: Unauthenticated Session Hijacking via Race Condition on Global Session Buffer

published 2026-06-10 4 mo ago modified 2026-07-23 3 mo ago also EUVD-2026-36194

cvss: 8.8; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.3%; EPSS 0.3% chance of exploitation in 30 days, percentile 22%
public exploits: 0; none known

Pi-hole FTL is the core engine of the Pi-hole network-level advertisement and tracker blocker. Prior to version 6.6.1, Pi-hole FTL contains a race condition vulnerability in the HTTP session management subsystem, introduced with the v6.0 rewrite of the embedded CivetWeb-based web server. This issue has been patched in version 6.6.1.

Patch / fix

fixed in 1 links 1

pi-hole ftldns 6.6.1

github.com/pi-hole/FTL/releases/tag/v6.6.1 release

CISA SSVC

Exploitation: Proof of concept is public
Automatable: no
Technical impact: total
Assessed: 4 mo ago (2026-06-11)

Exploit prediction

0.29% chance of exploitation in the next 30 days, higher than 22% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

github.com https://github.com/pi-hole/FTL/security/advisories/GHSA-9ff5-f3v5-2xc7 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by	version	score	vector
CNA	3.1	8.8	CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

Affected products

pi-hole FTL

Classification

Weakness

CWE-362 Concurrent Execution using Shared Resource with Improper Synchronization

References

Sources

CVE List CVE-2026-44693
NVD CVE-2026-44693

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.

Summary