CVE-2026-40209 (GCVE-0-2026-40209)

Vulnerability from cvelistv5 – Published: 2026-06-25 12:23 – Updated: 2026-06-25 13:56
VLAI
Title
Denial of service via IXFR queries
Summary
An attacker might be able to cause outgoing TCP connections to backend to be stuck until a timeout occurs instead of being released immediately, by sending IXFR queries. This could be used to cause a denial of service if there is a limit to the number of concurrent connections to this backend, or if the process runs out of file descriptors.
Severity
5.3 (Medium)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
SSVC
Exploitation: none Automatable: yes Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-06-25 13:56 UTC
CWE
  • Missing Release of Resource after Effective Lifetime
  • CWE-772 - Missing Release of Resource after Effective Lifetime
Assigner
OX
References
Impacted products
Vendor Product Version
PowerDNS DNSdist Affected: 1.9.0 , < 1.9.15 (semver)
Affected: 2.0.0 , < 2.0.7 (semver)
Create a notification for this product.
Date Public
2026-06-24 22:00
Credits
Qifan Zhang (Palo Alto Networks)
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.
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  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.


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