Browsertrix: Arbitrary Command Injection due to Improper Command Sanitization in Git URLs specified as Custom Behaviors

published 2026-09-17 52 d ago modified 2026-09-24 45 d ago also EUVD-2026-82422

cvss: 9.4; version 4.0, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 1.2%; EPSS 1.2% chance of exploitation in 30 days, percentile 68%
public exploits: 0; none known

Browsertrix is a high-fidelity, browser-based crawling service for web archiving that can be self-hosted or used through Webrecorder's hosted instance. From 1.15.0 until 1.22.8, Browsertrix improperly sanitizes Git URLs specified as Custom Behaviors, allowing command injection through /api/orgs/*/crawlconfigs/validate/custom-behavior. A user with crawler or administrator permission on the specific instance can supply a crafted Git URL that executes arbitrary operating-system commands in the backend pod. Open registration or hosted free-trial access can make the required role broadly obtainable. Successful exploitation can expose, modify, or delete application database records, archived items, browser profiles, storage data, proxy credentials, and other configured service data. This issue is fixed in version 1.22.8.

Patch / fix

links 2

CISA SSVC

Exploitation: none
Automatable: no
Technical impact: total
Assessed: 52 d ago (2026-09-17)

Exploit prediction

1.22% chance of exploitation in the next 30 days, higher than 68% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
CNA	4.0	9.4	CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H
CNA	4.0	9.4	CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Affected products

webrecorder browsertrix

Classification

Weakness

CWE-20 Improper Input Validation
CWE-77 Improper Neutralization of Special Elements used in a Command
CWE-78 Improper Neutralization of Special Elements used in an OS Command
CWE-88 Improper Neutralization of Argument Delimiters in a Command
CWE-250 Execution with Unnecessary Privileges

References

Sources

CVE List CVE-2026-54501
NVD CVE-2026-54501

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary