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CVE-2026-21723 (GCVE-0-2026-21723)

Vulnerability from cvelistv5 – Published: 2026-07-23 01:48 – Updated: 2026-08-27 17:22
VLAI
Title
CVE-2026-21723 Record
Summary
The alertmanager templates test endpoint (/api/alertmanager/grafana/config/api/v1/templates/test) can execute templates with no memory limits. Mass-executing templates in a short period causes OOM and crashes the Grafana service. The endpoint requires very low privileges and is exploitable with anonymous access enabled.
Severity
5.3 (Medium)
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H
SSVC
Exploitation: none Automatable: no Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-07-23 14:15 UTC
CWE
  • CWE-400 - Uncontrolled Resource Consumption
Assigner
References
Impacted products
Vendor Product Version CPE status
Grafana Grafana OSS Affected: 8.0.0 , ≤ 11.0.0 (semver)
Affected: 11.0.0 , ≤ 11.6.10 (semver)
Affected: 12.0.0 , ≤ 12.0.9 (semver)
Affected: 12.1.0 , ≤ 12.1.6 (semver)
Affected: 12.2.0 , ≤ 12.2.4 (semver)
Affected: 12.3.0 , ≤ 12.3.2 (semver)
guessed Create a notification for this product.
Date Public
2026-07-22 01:42
Credits
nacl (Researcher)
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.
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  • 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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Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.