Vulnerability · Published Aug 28, 2026 · Assigned by VulnCheck

CVE-2026-82287Rybbit Reflects Any Origin in CORS Responses While Allowing Credentials

High 8.1

In plain English

A high-severity security flaw in rybbit from rybbit-io. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.5% (higher than 44% of all known vulnerabilities).

Severity (CVSS 3.1)8.1High

Exploit odds (30 days)0.5%top 56.1% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official description

Rybbit before 2.7.0 contains a CORS misconfiguration vulnerability that allows attackers to bypass origin restrictions by reflecting any request origin in Access-Control-Allow-Origin responses while credentials are enabled. Attackers can issue credentialed cross-origin requests from any website to read analytics data, account information, and perform authenticated state-changing operations as the victim user.

Affected products (as reported)

Vendor	Product	Versions
rybbit-io	rybbit	0 – before 2.7.0

Weakness: CWE-942 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N

References

GitHub Issue #1038 issue-tracking
https://github.com/rybbit-io/rybbit product
Vulnerable code: index.ts technical-description
Fix commit patch
VulnCheck Advisory: Rybbit Reflects Any Origin in CORS Responses While Allowing Credentials third-party-advisory