CVE-2026-8888Network attack vector

Browsing denial of service via injected regex

Published Jun 3, 2026 · Updated Jun 3, 2026

Regular expression denial of service in Securly Chrome Extension 3.0.7 allows man-in-the-middle attackers to interrupt all browsing. The extension downloads config.json over HTTP and passes server-provided patterns to new RegExp() without checking their complexity. Exploitation requires control of the network path; injected patterns trigger catastrophic backtracking that hangs browsing without reported confidentiality or integrity impact.

CVSS severity7.5
High
EPSS probability0.43%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Regular expression denial of service in Securly Chrome Extension 3.0.7 allows man-in-the-middle attackers to interrupt all browsing. The extension downloads config.json over HTTP and passes server-provided patterns to new RegExp() without checking their complexity. Exploitation requires control of the network path; injected patterns trigger catastrophic backtracking that hangs browsing without reported confidentiality or integrity impact.

The record

CVE
CVE-2026-8888
Published
Jun 3, 2026
Updated
Jun 3, 2026
Vendor
Securly
Product
Securly Chrome Extension
Classifications
CWE-1333, CWE-917, T1499
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 3, 2026CVE publishedPublication date reported by the CVE source.
  2. Jun 3, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <=3.0.7

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Securly · Securly Chrome Extensionversion=0 <=3.0.7

Published CVSS scores

7.5NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
7.5CISA-ADPCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-1333Inefficient Regular Expression Complexity
CWE-917Improper Neutralization of Special Elements used in an Expression Language Statement ('Expression Language Injection')
T1499Endpoint Denial of Service

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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