VulnerabilityUndergoing Analysis

CVE-2026-11331

An attacker who knows (or guesses) that a resolver uses RPZ with wildcard CNAME policies can craft query names long enough to trigger a NAMETOOLONG error condition during RPZ processing.

HIGH 7.5EPSS 0.43%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (0.43%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

Description

An attacker who knows (or guesses) that a resolver uses RPZ with wildcard CNAME policies can craft query names long enough to trigger a NAMETOOLONG error condition during RPZ processing. This is not handled correctly and may lead to defeating the RPZ rule. It also may lead to an unexpected exit of the BIND 9 software. This issue affects BIND 9 versions 9.16.0 through 9.18.50, 9.20.0 through 9.20.24, 9.21.0 through 9.21.23, 9.16.8-S1 through 9.18.50-S1, and 9.20.9-S1 through 9.20.24-S1.

CVSS 3.1: 7.5 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
EPSS: 0.43% probability · 36th percentile
CISA KEV: Not listed
Weakness: CWE-790
Source: security-officer@isc.org

References

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.