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

> CVE-2025-1521: PostHog slack_incoming_webhook Server-Side Request Forgery Information Disclosure Vulnerability. CVSS 7.1 (CVSS 3.1).

Canonical: https://rewindex.com/cve/CVE-2025-1521
Last updated: 2026-06-17T08:39:17Z

- Published: 2025-04-23 16:45 UTC · Updated: 2026-06-17 08:39 UTC · Assigner: zdi
- CVSS: 7.1 (CVSS 3.1) · Severity: High · Vector: CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:N
- EPSS: 0.67%, 52th percentile (scored 2026-10-25)
- CISA KEV: no
- CWE: CWE-918

## 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 vendors and products

- PostHog: PostHog

## Tracked companies

- [PostHog](https://rewindex.com/company/posthog.md)

## References

- [CVE record on cve.org](https://www.cve.org/CVERecord?id=CVE-2025-1521)
- [NVD entry](https://nvd.nist.gov/vuln/detail/CVE-2025-1521)
- [https://github.com/PostHog/posthog/commit/6e8f035f9acd339c5ba87ba6ea40fc1ab3053d42](https://github.com/PostHog/posthog/commit/6e8f035f9acd339c5ba87ba6ea40fc1ab3053d42)
- [https://www.zerodayinitiative.com/advisories/ZDI-25-096/](https://www.zerodayinitiative.com/advisories/ZDI-25-096/)

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_Sources: CVE records from the CVE Program (cve.org). CVE® is a registered trademark of The MITRE Corporation. (https://www.cve.org/) This product uses data from the NVD API but is not endorsed or certified by the NVD. (https://nvd.nist.gov/) Known Exploited Vulnerabilities catalog from CISA. (https://www.cisa.gov/known-exploited-vulnerabilities-catalog) EPSS scores from FIRST (Exploit Prediction Scoring System). (https://www.first.org/epss/)_


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Canonical: https://rewindex.com/cve/CVE-2025-1521 · Markdown: https://rewindex.com/cve/CVE-2025-1521.md · JSON: https://rewindex.com/api/v1/cves/CVE-2025-1521 · Data licensed CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/) · Generated 2026-10-26T03:13:36.402Z