CVE-2026-3591

Exploitation

Assessed, none found. CISA's assessment recorded neither public exploit code nor evidence of exploitation when it was made.

SSVC decision

• ExploitationnoneCISA recorded no public exploit code and no evidence of exploitation.
• AutomatablenoAt least one step from reconnaissance to exploitation cannot be reliably automated.
• Technical ImpactpartialSuccessful exploitation gives limited control of the vulnerable component.

CISA publishes the decision points, not a final SSVC decision. The decision also depends on mission and well-being impact, which is a property of your deployment rather than of the vulnerability.

EPSS probability

0.36% probability of exploitation activity in the next 30 days.

EPSS percentile

Ranks above 29.0% of scored records. A rank, not a probability.

NVD base score

5.4 (CVSS v3.x), scored by the NVD independently of the CNA.

NVD CVSS vector

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

NVD analysis status

Analyzed. NVD last modified this record on 2026-06-17.

Red Hat severity

Moderate. Red Hat's rating for its own products, not a CVSS rating.

Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.

Published

2026-03-25 13:34Z5 MO AGO

Last updated

2026-03-25 14:13Z5 MO AGO

Reserved

2026-03-05

Assigning CNA

isc

Record state

PUBLISHED

Severity

Medium (CVSS 5.4)

CNA CVSS vector

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

Weaknesses

• CWE-305Authentication Bypass by Primary WeaknessBase
• CWE-562Return of Stack Variable AddressBase
• CWE-825Expired Pointer DereferenceBase

Data version

5.2

Document digest

43543ddab4e4bedf2376f976dbabddc8d0f108f70c2a4ebb6f95a9c78b0a9e80

• kb.isc.orgCVE-2026-3591https://kb.isc.org/docs/cve-2026-3591vendor-advisory
• downloads.isc.orghttps://downloads.isc.org/isc/bind9/9.20.21patch
• downloads.isc.orghttps://downloads.isc.org/isc/bind9/9.21.20patch