Account data theft via credentialed origin reflection
Published Aug 28, 2026 · Updated Aug 28, 2026
CORS misconfiguration in Rybbit before 2.7.0 allows remote attackers to read protected analytics data through a victim's browser. The Fastify CORS registration in server/src/index.ts accepts every Origin value and enables credentials, causing responses to reflect untrusted origins. Exploitation requires a logged-in victim to visit an attacker-controlled website; the site can read account data and submit authenticated state-changing requests with the victim's session.
Summary
What happened
CORS misconfiguration in Rybbit before 2.7.0 allows remote attackers to read protected analytics data through a victim's browser. The Fastify CORS registration in server/src/index.ts accepts every Origin value and enables credentials, causing responses to reflect untrusted origins. Exploitation requires a logged-in victim to visit an attacker-controlled website; the site can read account data and submit authenticated state-changing requests with the victim's session.
The record
- CVE
- CVE-2026-82287
- Published
- Aug 28, 2026
- Updated
- Aug 28, 2026
- Vendor
- Rybbit
- Product
- Rybbit
- Classifications
- CWE-942, T1185
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Aug 28, 2026CVE publishedPublication date reported by the CVE source.
- Aug 28, 2026Record 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=0 <2.7.0
What conditions does exploitation require?
What is affected?
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
- Credentialed cross-origin DELETE 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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