CVE-2026-3039 | BIND 9 server memory exhaustion during GSS-API TKEY negotiation

BIND servers that are configured to use TKEY-based authentication via GSS-API tokens are vulnerable to excessive memory consumption when receiving and processing maliciously-constructed packets. Typically these servers will be found in Active Directory integrated DNS deployments and/or Kerberos-secured DNS environments. This issue affects BIND 9 versions 9.0.0 through 9.16.50, 9.18.0 through 9.18.48, 9.20.0 through 9.20.22, 9.21.0 through 9.21.21, 9.9.3-S1 through 9.16.50-S1, 9.18.11-S1 through 9.18.48-S1, and 9.20.9-S1 through 9.20.22-S1.

Published: 2026-05-20 Last update: 2026-05-21 Assigner: [email protected] Source: [email protected]
NVD Status：Analyzed，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2026-3039 is rated Low Risk (35.7/100): CVSS High severity, with low exploitation likelihood (EPSS 0.05%). Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2026-3039

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-05-21 — 0.05% —

Full EPSS history (1 record total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-3039

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.5 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.9 3.6 [email protected]

Weakness enumeration for CVE-2026-3039

GitHub Security Advisory for CVE-2026-3039

GHSA-p65f-mhrm-vhrc · Severity: high — BIND servers that are configured to use TKEY-based authentication via GSS-API tokens are...

OS Trackers for CVE-2026-3039

vendor priority summary link
debian not yet assigned CVE-2026-3039 not yet assigned priority: Debian including 1 source packages (bind9), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 4, open 1. https://security-tracker.debian.org/tracker/CVE-2026-3039
redhat high — https://access.redhat.com/security/cve/CVE-2026-3039
suse high CVE-2026-3039 severity important: SUSE including 12 source package names (bind-9.18.49-150600.3.24.1, bind-9.20.23-1.1, …), 15 product×package rows across 3 product lines (SUSE Linux Enterprise Server 15 SP6-LTSS, SUSE Linux Enterprise Server for SAP Applications 15 SP6, openSUSE Tumbleweed): Fixed 9, First Fixed 6. https://www.suse.com/security/cve/CVE-2026-3039/
ubuntu medium CVE-2026-3039 medium priority: Ubuntu including 3 source packages (bind9, bind9-libs, isc-dhcp), 24 status rows across 9 suites (bionic, focal, jammy, noble, questing, resolute, trusty, upstream, xenial): needs-triage 12, released 5, not-affected 4, DNE 3. https://ubuntu.com/security/CVE-2026-3039

Affected software / configurations for CVE-2026-3039

Vendor Product Version Raw CPE
isc bind >= 9.0.0, <= 9.16.50 cpe:2.3:a:isc:bind:*:*:*:*:-:*:*:*
isc bind >= 9.18.0, < 9.18.49 cpe:2.3:a:isc:bind:*:*:*:*:-:*:*:*
isc bind >= 9.20.0, < 9.20.23 cpe:2.3:a:isc:bind:*:*:*:*:-:*:*:*
isc bind >= 9.21.0, < 9.21.22 cpe:2.3:a:isc:bind:*:*:*:*:-:*:*:*

References for CVE-2026-3039

cvelogic Threat Intelligence