CVE-2026-2291

Description

dnsmasqs extract_name() function can be abused to cause a heap buffer overflow, allowing an attacker to inject false DNS cache entries, which could result in DNS lookups to redirect to an attacker-controlled IP address, or to cause a DoS.

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CVSS v3.1 Score

7.3

HIGH

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L

EPSS — Exploit Prediction

0.0008

Probability of exploitation

0.23%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

References

Other References

https://github.com/NixOS/nixpkgs/pull/519082 https://github.com/NixOS/nixpkgs/pull/519093 https://github.com/pi-hole/FTL/releases/tag/v6.6.2 https://lists.thekelleys.org.uk/pipermail/dnsmasq-discuss/2026q2/018471.html https://thekelleys.org.uk/dnsmasq/CVE/ https://www.kb.cert.org/vuls/id/471747 https://www.suse.com/security/cve/CVE-2026-2291.html

Frequently Asked Questions

What is CVE-2026-2291? +

dnsmasqs extract_name() function can be abused to cause a heap buffer overflow, allowing an attacker to inject false DNS cache entries, which could result in DNS lookups to redirect to an attacker-controlled IP address, or to cause a DoS. It has a CVSS v3.1 base score of 7.3 (HIGH).

How severe is CVE-2026-2291? +

CVE-2026-2291 has a CVSS v3.1 score of 7.3 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching. The EPSS score is 0.0008, placing it in the 0th percentile for exploitation probability.

How do I check if I'm vulnerable to CVE-2026-2291? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.