CVE-2026-8889Network attack vector

Unspecified impact via weak URL hashing

Published Jun 3, 2026 · Updated Jun 3, 2026

Use of weak hashing in Securly Chrome Extension 3.0.7 and earlier allows attackers to cause unspecified impact via URL matching. The IWF CSAM and CIPA blocklist matchers use SHA-1 digests to decide whether URLs match protected lists, relying on a hash that lacks modern collision resistance. The extension performs filtering only on Chrome OS for registered school domains, and public sources do not explain a demonstrated attack or a bounded CVE-specific consequence.

CVSS severity7.5
High
EPSS probability0.25%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Use of weak hashing in Securly Chrome Extension 3.0.7 and earlier allows attackers to cause unspecified impact via URL matching. The IWF CSAM and CIPA blocklist matchers use SHA-1 digests to decide whether URLs match protected lists, relying on a hash that lacks modern collision resistance. The extension performs filtering only on Chrome OS for registered school domains, and public sources do not explain a demonstrated attack or a bounded CVE-specific consequence.

The record

CVE
CVE-2026-8889
Published
Jun 3, 2026
Updated
Jun 3, 2026
Vendor
Securly
Product
Securly Chrome Extension
Classifications
CWE-328, CWE-407
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

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

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-328Use of Weak Hash
CWE-407Inefficient Algorithmic Complexity

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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