Record ordering based unexpected exit with CNAME or DNAME
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Denial of service
- Confidentiality · integrity · availability
- None · None · High
- Fix status
- Fixed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA and Red Hat. Impact type from CWE-617.
Summary
The issue is unexpected program termination based on ordering and/or specific content in responses to queries for CNAME or DNAME, and A records. Specifically, if a client queries for a DNAME and A record below the DNAME to the resolver, and the authoritative server responds positively to the A query but delays the DNAME response and later responds negatively, `named` may quit unexpectedly. Or, if a client queries for a CNAME and A record for the same name to the resolver, and the authoritative server responds positively to the A query but delays the CNAME response and later responds with a self-referential CNAME, the same failure may occur. This issue affects BIND 9 versions 9.18.0 through 9.18.50, 9.20.0 through 9.20.24, 9.18.11-S1 through 9.18.50-S1, and 9.20.9-S1 through 9.20.24-S1.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- Yes
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| ISC | BIND 9 | 9.18.0 – 9.18.50; 9.20.0 – 9.20.24; 9.18.11-S1 – 9.18.50-S1; 9.20.9-S1 – 9.20.24-S1 | — | No fix listed | CNA |
- BIND 9 VendorISC Affected 9.18.0 – 9.18.50; 9.20.0 – 9.20.24; 9.18.11-S1 – 9.18.50-S1; 9.20.9-S1 – 9.20.24-S1 Fixed in — No fix listed CNA
CPE configurations NVD · 4
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:isc:bind:*:*:*:*:-:*:*:* | 9.18.0 – 9.18.50 | Vulnerable | ISC |
| cpe:2.3:a:isc:bind:*:*:*:*:supported_preview:*:*:* | 9.18.11 – 9.18.50 | Vulnerable | ISC |
| cpe:2.3:a:isc:bind:*:*:*:*:-:*:*:* | 9.20.0 – 9.20.24 | Vulnerable | ISC |
| cpe:2.3:a:isc:bind:*:*:*:*:supported_preview:*:*:* | 9.20.9 – 9.20.24 | Vulnerable | ISC |
- cpe:2.3:a:isc:bind:*:*:*:*:-:*:*:* Versions 9.18.0 – 9.18.50 Vulnerable ·ISC
- cpe:2.3:a:isc:bind:*:*:*:*:supported_preview:*:*:* Versions 9.18.11 – 9.18.50 Vulnerable ·ISC
- cpe:2.3:a:isc:bind:*:*:*:*:-:*:*:* Versions 9.20.0 – 9.20.24 Vulnerable ·ISC
- cpe:2.3:a:isc:bind:*:*:*:*:supported_preview:*:*:* Versions 9.20.9 – 9.20.24 Vulnerable ·ISC
Remediation
Red Hat 1 advisory
- RHSA-2026:54071 Released 2026-08-12 · Red Hat rating ImportantRed Hat Hardened Images RPMs Security Update
- Red Hat Hardened Images bind-32:9.20.26-0.1.hum1@aarch64, bind-32:9.20.26-0.1.hum1@src, bind-32:9.20.26-0.1.hum1@x86_64 +12
Vendor assessments
Red Hat
Red Hat rating: Important. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Hardened Images | Fixed | RHSA-2026:54071 |
Not affected: 7 products
- Red Hat Enterprise Linux 10
- Red Hat Enterprise Linux 6
- Red Hat Enterprise Linux 7
- Red Hat Enterprise Linux 8
- Red Hat Enterprise Linux 9
- Red Hat OpenShift Container Platform 4
- Red Hat OpenShift Container Platform 5
Timeline
- 2026-10-02 Threatist record created from CVE-2026-12617
- 2026-10-03 Alias added: GHSA-cc7q-gqfw-hrm4
- 2026-11-05 Affected versions changed · Red Hat
References
Advisory 1
More ISC Bind vulnerabilities
- TI-2015-04610 Assertion failure in ISC BIND named via TKEY queries KEVCVSS 3.1HIGH 7.5
- TI-2023-27571 Certain DNSSEC aspects of the DNS protocol (in RFC 4033, 4034, 4035, 6840, and related… CVSS 3.1HIGH 7.5
- TI-2021-07476 A second vulnerability in BIND's GSSAPI security policy negotiation can be targeted by a buffer overflow attack CVSS 3.1CRITICAL 9.8
- TI-2023-27773 The Closest Encloser Proof aspect of the DNS protocol (in RFC 5155 when RFC 9276 guidance… CVSS 3.1HIGH 7.5
- TI-2020-06910 A logic error in code which checks TSIG validity can be used to trigger an assertion failure in tsig.c CVSS 3.1HIGH 7.5
- TI-2016-02320 buffer.c in named in ISC BIND 9 before 9.9.9-P3, 9.10.x before 9.10.4-P3, and 9.11.x… CVSS 3.0HIGH 7.5
Sources
- CVE-2026-12617 · CVE Program
- CVE-2026-12617 · NVD
- FIRST EPSS
- GHSA-cc7q-gqfw-hrm4 · GitHub Advisory Database · CC BY 4.0
- CVE-2026-12617 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences