CVE-2026-8888

Description

Version 3.0.7 of the Securly Chrome Extension downloads config.json over HTTP and compiles server-provided patterns as JavaScript regular expressions via new RegExp() without complexity validation. An on-path attacker can inject specific patterns to cause catastrophic backtracking, resulting in denial of service on all browsing.

CVSS v3.1 Score

7.5

HIGH

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS — Exploit Prediction

0.0043

Probability of exploitation

0.35%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-917 CWE-917

CWE-1333 CWE-1333

Affected Products

Vendor	Product	Versions
securly	securly	All

References

Other References

https://kb.cert.org/vuls/id/595768

Frequently Asked Questions

What is CVE-2026-8888? +

Version 3.0.7 of the Securly Chrome Extension downloads config.json over HTTP and compiles server-provided patterns as JavaScript regular expressions via new RegExp() without complexity validation. An on-path attacker can inject specific patterns to cause catastrophic backtracking, resulting in denial of service on all browsing. It has a CVSS v3.1 base score of 7.5 (HIGH).

How severe is CVE-2026-8888? +

CVE-2026-8888 has a CVSS v3.1 score of 7.5 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching. The EPSS score is 0.0043, placing it in the 0th percentile for exploitation probability.

What products are affected by CVE-2026-8888? +

CVE-2026-8888 affects products from securly, specifically: securly. Check the affected products table above for specific version ranges.

How do I check if I'm vulnerable to CVE-2026-8888? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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