7.5

CVE-2026-12617: isc bind 9 Reachable Assertion

CVSS: 7.5v3.1HighUndergoing analysis
AliasesALPINE-CVE-2026-12617UBUNTU-CVE-2026-12617DEBIAN-CVE-2026-12617
Published 22-07-2026Last modified 22-07-2026
Open JSON

Vulnerability summary

CVE-2026-12617 is a high (CVSS 7.5) Reachable Assertion vulnerability in isc bind 9. EPSS estimates a 0.50% chance of exploitation in the next 30 days, higher than 41.6% of scored vulnerabilities.

Overall risk
30/100
0100
Medium · default modelHow is this calculated?
CVSS score
7.5/10
010
High · v3.1 (CVE.org)
EPSS score
0.50%
0%100%
Low · 0.00 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 7 · Related 5
MGASA-2026-0331OPENSUSE-SU-2026:11375-1OPENSUSE-SU-2026:21489-1RHSA-2026:54071SUSE-SU-2026:3426-1SUSE-SU-2026:3452-1

Timeline

  1. 22-07-2026
    PublishedVulnerability first disclosed.
  2. 22-07-2026
    Last modifiedVulnerability information updated.

Description

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.

CVSS metrics

5 scores · 5 sources · 1 version

EPSS trend

Probability

0.50%

Chance of exploitation in the next 30 days

Percentile

42%

Versus all other CVEs

30-day change

0.00 pp

From 0.50% on 19-09-2026

19-09-202619-10-2026
EPSS score
0.50%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Ubuntu3 products
  • bind9All versions (No fix recorded) | < 1:9.18.39-0ubuntu0.22.04.5 | < 1:9.18.39-0ubuntu0.24.04.6 | < 1:9.20.24-1ubuntu0.2
  • bind9-libsAll versions (No fix recorded)
  • isc-dhcpAll versions (No fix recorded)
Alpine1 product
  • bind< 9.20.26-r0
Debian1 product
  • bind9< 1:9.18.49-1~deb12u2 | < 1:9.20.26-1~deb13u1 | < 1:9.20.26-1
Isc1 product
  • 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

4 vendors · 6 products

References

8 links