CVE-2026-3591 (GCVE-0-2026-3591)

Vulnerability from cvelistv5 – Published: 2026-03-25 13:34 – Updated: 2026-03-25 14:13
VLAI?
Title
A stack use-after-return flaw in SIG(0) handling code may enable ACL bypass
Summary
A use-after-return vulnerability exists in the `named` server when handling DNS queries signed with SIG(0). Using a specially-crafted DNS request, an attacker may be able to cause an ACL to improperly (mis)match an IP address. In a default-allow ACL (denying only specific IP addresses), this may lead to unauthorized access. Default-deny ACLs should fail-secure. This issue affects BIND 9 versions 9.20.0 through 9.20.20, 9.21.0 through 9.21.19, and 9.20.9-S1 through 9.20.20-S1. BIND 9 versions 9.18.0 through 9.18.46 and 9.18.11-S1 through 9.18.46-S1 are NOT affected.
Severity ?
5.4 (Medium)
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N
CWE
  • CWE-562 - Return of Stack Variable Address
  • CWE-305 - Authentication Bypass by Primary Weakness
Assigner
isc
References
Impacted products
Vendor Product Version
ISC BIND 9 Affected: 9.20.0 , ≤ 9.20.20 (custom)
Affected: 9.21.0 , ≤ 9.21.19 (custom)
Affected: 9.20.9-S1 , ≤ 9.20.20-S1 (custom)
Unaffected: 9.18.0 , ≤ 9.18.46 (custom)
Unaffected: 9.18.11-S1 , ≤ 9.18.46-S1 (custom)
Create a notification for this product.
Date Public ?
2026-03-25 00:00
Credits
ISC would like to thank Mcsky23 for bringing this vulnerability to our attention.
Show details on NVD website
To clipboard 

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  • 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.



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