CVE-2026-3593 (GCVE-0-2026-3593)

Vulnerability from cvelistv5 – Published: 2026-05-20 13:09 – Updated: 2026-05-20 13:40
VLAI
Title
Heap use-after-free vulnerability in BIND 9 DNS-over-HTTPS implementation
Summary
A use-after-free vulnerability exists within the DNS-over-HTTPS implementation. This issue affects BIND 9 versions 9.20.0 through 9.20.22, 9.21.0 through 9.21.21, and 9.20.9-S1 through 9.20.22-S1. BIND 9 versions 9.18.0 through 9.18.48 and 9.18.11-S1 through 9.18.48-S1 are NOT affected.
Severity
7.4 (High)
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:H
SSVC
Exploitation: none Automatable: no Technical Impact: partial
CISA Coordinator (v2.0.3)
CWE
Assigner
isc
References
Impacted products
Vendor Product Version
ISC BIND 9 Affected: 9.20.0 , ≤ 9.20.22 (custom)
Affected: 9.21.0 , ≤ 9.21.21 (custom)
Affected: 9.20.9-S1 , ≤ 9.20.22-S1 (custom)
Unaffected: 9.18.0 , ≤ 9.18.48 (custom)
Unaffected: 9.18.11-S1 , ≤ 9.18.48-S1 (custom)
Create a notification for this product.
Date Public
2026-05-20 00:00
Credits
ISC would like to thank Naresh Kandula Parmar (Nottiboy) for bringing this vulnerability to our attention.
Show details on NVD website
To clipboard 

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Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

Sightings

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Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.


Detection rules are retrieved from Rulezet.