CVE-2026-55879: XSS (CVSS 9.3)

Description

OpenReplay is a self-hosted session replay suite. From 1.24.0 before 1.25.0, the OpenReplay tracking SDK accepts custom event names and captured page URLs from any visitor using a public project key, stores them in ClickHouse without output encoding, and later renders them in the authenticated dashboard through TextEllipsis and the event-details modal, allowing an unauthenticated attacker to store script that executes in the dashboard origin, reads the session JWT from localStorage, and takes over a dashboard account. This issue is fixed in version 1.25.0.

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CVSS v3.1 Score

9.3

CRITICAL

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:N

EPSS — Exploit Prediction

0.0027

Probability of exploitation

0.19%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-79 Cross-site Scripting (XSS)

References

Other References

https://github.com/openreplay/openreplay/commit/ec41f4425a99c478a4418adbd2f094ab6a8b0daf https://github.com/openreplay/openreplay/releases/tag/v1.25.0 https://github.com/openreplay/openreplay/security/advisories/GHSA-3mfc-7hf4-jfxh

Frequently Asked Questions

What is CVE-2026-55879? +

OpenReplay is a self-hosted session replay suite. From 1.24.0 before 1.25.0, the OpenReplay tracking SDK accepts custom event names and captured page URLs from any visitor using a public project key, stores them in ClickHouse without output encoding, and later renders them in the authenticated dashboard through TextEllipsis and the event-details modal, allowing an unauthenticated attacker to store script that executes in the dashboard origin, reads the session JWT from localStorage, and takes over a dashboard account. This issue is fixed in version 1.25.0. It has a CVSS v3.1 base score of 9.3 (CRITICAL).

How severe is CVE-2026-55879? +

CVE-2026-55879 has a CVSS v3.1 score of 9.3 out of 10, rated CRITICAL. This is a critical vulnerability that should be patched immediately. The EPSS score is 0.0027, placing it in the 0th percentile for exploitation probability.

How do I check if I'm vulnerable to CVE-2026-55879? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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