Account takeover via same-origin SVG favicon scripts
Published Jun 4, 2025 · Updated Jun 4, 2025
Stored XSS in FreshRSS before 1.26.2 allows remote authenticated users to execute JavaScript through an attacker-controlled feed. The f.php favicon endpoint serves unsanitized scripted SVG content without CSP, allowing a sandboxed same-origin iframe to run it on the feeds page. Exploitation requires an attacker account and control of a subscribed feed; execution can take over the victim account and, for an administrator, reach user deletion or server code execution.
Summary
What happened
Stored XSS in FreshRSS before 1.26.2 allows remote authenticated users to execute JavaScript through an attacker-controlled feed. The f.php favicon endpoint serves unsanitized scripted SVG content without CSP, allowing a sandboxed same-origin iframe to run it on the feeds page. Exploitation requires an attacker account and control of a subscribed feed; execution can take over the victim account and, for an administrator, reach user deletion or server code execution.
The record
- CVE
- CVE-2025-31136
- Published
- Jun 4, 2025
- Updated
- Jun 4, 2025
- Vendor
- FreshRSS
- Product
- FreshRSS
- Classifications
- CWE-79, T1203
- Attack vector
- network
- Privileges
- authenticated
Timeline
How it unfolded
- Jun 4, 2025CVE publishedPublication date reported by the CVE source.
- Jun 4, 2025Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=< 1.26.2
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- FreshRSS malicious-feed and SVG-favicon proof of conceptproof of concept · demonstrated
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
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Your stack
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