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CVE-2026-33621— PinchTab: Unapplied Rate Limiting Middleware Allows Unbounded Brute-Force of API Token

Quick assessment

Affected
pinchtab pinchtab
Exploitation
No confirmed in-the-wild exploitation; assess based on exposure
Recommended action
Check the vendor advisory and references for a fixed version. If immediate upgrade is impossible, restrict exposure and increase monitoring.

pinchtab是Pinchtab开源的一个AI代理浏览器控制工具。 pinchtab 0.7.7至0.8.4版本存在安全漏洞，该漏洞源于请求限制保护不完整，可能削弱纵深防御。

CVSS 4.8 · Medium EPSS 0.32% · P25

Possible ATT&CK Techniques 1 AI

T1190 · Exploit Public-Facing Application
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I. Basic Information for CVE-2026-33621

Vulnerability Information
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Vulnerability Title
PinchTab: Unapplied Rate Limiting Middleware Allows Unbounded Brute-Force of API Token
Source: CVE Program / CVE List V5
Vulnerability Description
PinchTab is a standalone HTTP server that gives AI agents direct control over a Chrome browser. PinchTab `v0.7.7` through `v0.8.4` contain incomplete request-throttling protections for auth-checkable endpoints. In `v0.7.7` through `v0.8.3`, a fully implemented `RateLimitMiddleware` existed in `internal/handlers/middleware.go` but was not inserted into the production HTTP handler chain, so requests were not subject to the intended per-IP throttle. In the same pre-`v0.8.4` range, the original limiter also keyed clients using `X-Forwarded-For`, which would have allowed client-controlled header spoofing if the middleware had been enabled. `v0.8.4` addressed those two issues by wiring the limiter into the live handler chain and switching the key to the immediate peer IP, but it still exempted `/health` and `/metrics` from rate limiting even though `/health` remained an auth-checkable endpoint when a token was configured. This issue weakens defense in depth for deployments where an attacker can reach the API, especially if a weak human-chosen token is used. It is not a direct authentication bypass or token disclosure issue by itself. PinchTab is documented as local-first by default and uses `127.0.0.1` plus a generated random token in the recommended setup. PinchTab's default deployment model is a local-first, user-controlled environment between the user and their agents; wider exposure is an intentional operator choice. This lowers practical risk in the default configuration, even though it does not by itself change the intrinsic base characteristics of the bug. This was fully addressed in `v0.8.5` by applying `RateLimitMiddleware` in the production handler chain, deriving the client address from the immediate peer IP instead of trusting forwarded headers by default, and removing the `/health` and `/metrics` exemption so auth-checkable endpoints are throttled as well.
Source: CVE Program / CVE List V5
CVSS Information
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N
Source: CVE Program / CVE List V5
Vulnerability Type
使用欺骗进行的认证绕过
Source: CVE Program / CVE List V5
Vulnerability Title
pinchtab 安全漏洞
Source: CNNVD (China National Vulnerability Database)
Vulnerability Description
pinchtab是Pinchtab开源的一个AI代理浏览器控制工具。 pinchtab 0.7.7至0.8.4版本存在安全漏洞，该漏洞源于请求限制保护不完整，可能削弱纵深防御。
Source: CNNVD (China National Vulnerability Database)
CVSS Information
N/A
Source: CNNVD (China National Vulnerability Database)
Vulnerability Type
N/A
Source: CNNVD (China National Vulnerability Database)

Affected Products

Vendor Product Affected Versions CPE Subscribe
pinchtab pinchtab >= 0.7.7, < 0.8.5 -

II. Public POCs for CVE-2026-33621

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III. Intelligence Information for CVE-2026-33621

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Patches & Fixes for CVE-2026-33621 (1)

Other References for CVE-2026-33621 (1)

Same Patch Batch · pinchtab · 2026-03-26 · 5 CVEs total

CVE-2026-33623 6.7 MEDIUM PinchTab: OS Command Injection via Profile Name in Windows Cleanup Routine Enables Arbitra
CVE-2026-33620 4.3 MEDIUM PinchTab: API Bearer Token Exposed in URL Query Parameter via Server Logs and Intermediary
CVE-2026-33619 4.1 MEDIUM PinchTab has Unauthenticated Blind SSRF in Task Scheduler via Unvalidated callbackUrl
CVE-2026-33622 A PinchTab Security Policy Bypass in /wait Allows Arbitrary JavaScript Execution

IV. Related Vulnerabilities

Same product: pinchtab
Same vendor: pinchtab
Same weakness: CWE-290