What’s Vulnerable › Vulnerabilities

CVE-2020-26282: Template Injection in BrowserUp Proxy

• Severity: critical (CVSS 10.0 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 4.8% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2020-12-24 · updated 2026-06-17
• Weakness: CWE-74

Description

BrowserUp Proxy allows you to manipulate HTTP requests and responses, capture HTTP content, and export performance data as a HAR file. BrowserUp Proxy works well as a standalone proxy server, but it is especially useful when embedded in Selenium tests. A Server-Side Template Injection was identified in BrowserUp Proxy enabling attackers to inject arbitrary Java EL expressions, leading to unauthenticated Remote Code Execution (RCE) vulnerability. This has been patched in version 2.1.2.

Affected products

• browserup-proxy: before 2.1.2 — fixed in 2.1.2

How to fix

Upgrade to a fixed version: browserup-proxy 2.1.2. Check the vendor advisory for mitigations.

References

• https://github.com/browserup/browserup-proxy/commit/4b38e7a3e20917e5c3329d0d4e9590bed9d578ab
• https://github.com/browserup/browserup-proxy/releases/tag/v2.1.2
• https://github.com/browserup/browserup-proxy/security/advisories/GHSA-wmfg-55f9-j8hq
• https://securitylab.github.com/research/bean-validation-RCE
• https://github.com/browserup/browserup-proxy/commit/4b38e7a3e20917e5c3329d0d4e9590bed9d578ab
• https://github.com/browserup/browserup-proxy/releases/tag/v2.1.2
• https://github.com/browserup/browserup-proxy/security/advisories/GHSA-wmfg-55f9-j8hq
• https://securitylab.github.com/research/bean-validation-RCE

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