Vulnerability · Published Apr 23, 2025 · Assigned by zdi

CVE-2025-1521PostHog slack_incoming_webhook Server-Side Request Forgery Information Disclosure Vulnerability

High 7.1

In plain English

A high-severity server-side request forgery in PostHog from PostHog. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.7% (higher than 52% of all known vulnerabilities).

Severity (CVSS 3.0)7.1High

Exploit odds (30 days)0.7%top 48.0% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official description

PostHog slack_incoming_webhook Server-Side Request Forgery Information Disclosure Vulnerability. This vulnerability allows remote attackers to disclose sensitive information on affected installations of PostHog. Authentication is required to exploit this vulnerability. The specific flaw exists within the processing of the slack_incoming_webhook parameter. The issue results from the lack of proper validation of a URI prior to accessing resources. An attacker can leverage this vulnerability to execute code in the context of the service account. Was ZDI-CAN-25352.

Affected products (as reported)

Vendor	Product	Versions
PostHog	PostHog	b8817c14065c23159dcf52849f0bdcd12516c43e

Weakness: CWE-918 · Vector: CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:N

References

ZDI-25-096 x_research-advisory
vendor-provided URL vendor-advisory