7.5

CVE-2026-13204: isc bind 9 Reachable Assertion

CVSS: 7.5v3.1HighUndergoing analysis
AliasesALPINE-CVE-2026-13204MGASA-2026-0399UBUNTU-CVE-2026-13204
Published 22-07-2026Last modified 22-07-2026

Vulnerability summary

CVE-2026-13204 is a high (CVSS 7.5) Reachable Assertion vulnerability in isc bind 9. EPSS estimates a 0.52% chance of exploitation in the next 30 days, higher than 43.1% 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
0.52%
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 22 · Related 10

Timeline

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

Description

If a provably insecure domain is covered by both an NSEC and NSEC3 record at the parent, and there exist an RRSIG for only one of these types, then BIND may exit unexpectedly with an assertion while validating this proof. This issue affects BIND 9 versions 9.11.0 through 9.18.50, 9.20.0 through 9.20.24, 9.21.0 through 9.21.23, 9.11.3-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

0.52%

Chance of exploitation in the next 30 days

Percentile

43%

Versus all other CVEs

30-day change

0.00 pp

From 0.52% on 19-09-2026

19-09-202619-10-2026
EPSS score
0.52%

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) | < 1:9.9.5.dfsg-3ubuntu0.19+esm15 | < 1:9.10.3.dfsg.P4-8ubuntu1.19+esm11 | < 1:9.11.3+dfsg-1ubuntu1.19+esm6 | < 1:9.18.30-0ubuntu0.20.04.2+esm3 | < 1:9.18.39-0ubuntu0.22.04.6 | < 1:9.18.39-0ubuntu0.24.04.7 | < 1:9.20.24-1ubuntu0.3
  • 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≥ 9.11.0, ≤ 9.18.50 | ≥ 9.20.0, ≤ 9.20.24 | ≥ 9.21.0, ≤ 9.21.23 | ≥ 9.11.3-S1, ≤ 9.18.50-S1 | ≥ 9.20.9-S1, ≤ 9.20.24-S1
Mageia1 product
  • bind< 9.18.50-1.1.mga9

5 vendors · 7 products

References

12 links
Show all 12 references