CVE-2023-40577

Alertmanager UI is vulnerable to stored XSS via the /api/v1/alerts endpoint

MEDIUM
5.4
CVSS Score
Published: August 25, 2023 at 12:12 AM UTC
Updated: June 17, 2026 at 06:18 AM UTC
2 products affected across 2 vendorsDebian LinuxAlertmanager

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Severity
MEDIUM5.4
Exploit prediction
EPSS 0.6%
SSVC
No known exploit

Description

Alertmanager handles alerts sent by client applications such as the Prometheus server. An attacker with the permission to perform POST requests on the /api/v1/alerts endpoint could be able to execute arbitrary JavaScript code on the users of Prometheus Alertmanager. This issue has been fixed in Alertmanager version 0.2.51.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

SSVC — Action Prioritization

SSVCNo known exploitAutomatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

Attack Vector
NETWORK
Complexity
LOW
Privileges
LOW
User Interaction
REQUIRED
Scope
CHANGED
Confidentiality
LOW
Integrity
LOW
Availability
NONE
Vector?

Quick Info

StatusMODIFIED
CWE
CWE-79

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