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CVE-2026-5950

5.3 MEDIUM

An unbounded resend loop vulnerability exists in the BIND 9 resolver state machine during bad-server handling, enabling a remote unauthen...

Published: 2026-05-20 · Last updated: 2026-05-21

Severity and scoring

CVSS
5.3 MEDIUM
Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
CWE
CWE-606

Affected products

VendorProduct
iscbind

Description

An unbounded resend loop vulnerability exists in the BIND 9 resolver state machine during bad-server handling, enabling a remote unauthenticated attacker to cause severe resource exhaustion by sending queries that trigger specific retry conditions. This issue affects BIND 9 versions 9.18.36 through 9.18.48, 9.20.8 through 9.20.22, 9.21.7 through 9.21.21, 9.18.36-S1 through 9.18.48-S1, and 9.20.9-S1 through 9.20.22-S1.

Source: NVD

References

Related CVEs

Same vendor

  • CVE-2026-5947 — Undefined behavior may result due to a race condition leading to a use-after-free violation (7.5 HIGH)
  • CVE-2026-5946 — Multiple flaws have been identified in `named` related to the handling of DNS messages whose CLASS is not Internet (`IN`) — for example, ... (7.5 HIGH)
  • CVE-2026-3593 — A use-after-free vulnerability exists within the DNS-over-HTTPS implementation (7.4 HIGH)
  • CVE-2026-3592 — BIND resolvers are vulnerable to an amplified resource consumption/exhaustion attack (5.3 MEDIUM)
  • CVE-2026-3039 — BIND servers that are configured to use TKEY-based authentication via GSS-API tokens are vulnerable to excessive memory consumption when ... (7.5 HIGH)

Same CWE

  • CVE-2026-41986 — Logic bypass vulnerability in the file system (2.4 LOW)
  • CVE-2026-1519 — If a BIND resolver is performing DNSSEC validation and encounters a maliciously crafted zone, the resolver may consume excessive CPU (7.5 HIGH)