FreshRSS is a self-hosted RSS feed aggregator. Prior to version 1.26.2, it's possible to run arbitrary JavaScript on the feeds page. This occurs by combining a cross-site scripting (XSS) issue that occurs in `f.php` when SVG favicons are downloaded from an attacker-controlled feed containing `<script>` tags inside of them that aren't sanitized, with the lack of CSP in `f.php` by embedding the malicious favicon in an iframe (that has `sandbox="allow-scripts allow-same-origin"` set as its attribute). An attacker needs to control one of the feeds that the victim is subscribed to, and also must have an account on the FreshRSS instance. Other than that, the iframe payload can be embedded as one of two options. The first payload requires user interaction (the user clicking on the malicious feed entry) with default user configuration, and the second payload fires instantly right after the user adds the feed or logs into the account while the feed entry is still visible. This is because of lazy image loading functionality, which the second payload bypasses. An attacker can gain access to the victim's account by exploiting this vulnerability. If the victim is an admin it would be possible to delete all users (cause damage) or execute arbitrary code on the server by modifying the update URL using fetch() via the XSS. Version 1.26.2 has a patch for the issue.
History

Tue, 10 Jun 2025 15:30:00 +0000

Type Values Removed Values Added
First Time appeared Freshrss
Freshrss freshrss
CPEs cpe:2.3:a:freshrss:freshrss:*:*:*:*:*:*:*:*
Vendors & Products Freshrss
Freshrss freshrss

Wed, 04 Jun 2025 21:15:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'poc', 'Technical Impact': 'total'}, 'version': '2.0.3'}


Wed, 04 Jun 2025 20:00:00 +0000

Type Values Removed Values Added
Description FreshRSS is a self-hosted RSS feed aggregator. Prior to version 1.26.2, it's possible to run arbitrary JavaScript on the feeds page. This occurs by combining a cross-site scripting (XSS) issue that occurs in `f.php` when SVG favicons are downloaded from an attacker-controlled feed containing `<script>` tags inside of them that aren't sanitized, with the lack of CSP in `f.php` by embedding the malicious favicon in an iframe (that has `sandbox="allow-scripts allow-same-origin"` set as its attribute). An attacker needs to control one of the feeds that the victim is subscribed to, and also must have an account on the FreshRSS instance. Other than that, the iframe payload can be embedded as one of two options. The first payload requires user interaction (the user clicking on the malicious feed entry) with default user configuration, and the second payload fires instantly right after the user adds the feed or logs into the account while the feed entry is still visible. This is because of lazy image loading functionality, which the second payload bypasses. An attacker can gain access to the victim's account by exploiting this vulnerability. If the victim is an admin it would be possible to delete all users (cause damage) or execute arbitrary code on the server by modifying the update URL using fetch() via the XSS. Version 1.26.2 has a patch for the issue.
Title FreshRSS vulnerable to Cross-site Scripting by <iframe>'ing a vulnerable same-origin page in a feed entry
Weaknesses CWE-79
References
Metrics cvssV3_1

{'score': 6.7, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:U/C:H/I:H/A:L'}


cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published: 2025-06-04T19:42:15.077Z

Updated: 2025-06-04T20:18:02.553Z

Reserved: 2025-03-26T15:04:52.627Z

Link: CVE-2025-31136

cve-icon Vulnrichment

Updated: 2025-06-04T20:17:54.037Z

cve-icon NVD

Status : Analyzed

Published: 2025-06-04T20:15:22.843

Modified: 2025-06-10T15:08:13.370

Link: CVE-2025-31136

cve-icon Redhat

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