How severe is CVE-2026-8879?

CVE-2026-8879 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2026-8879 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (29th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-8879?

CVE-2026-8879 affects Securly. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-8879?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

Does CVE-2026-8879 have an EU (EUVD) identifier?

Yes. CVE-2026-8879 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-34165.

When was CVE-2026-8879 published?

CVE-2026-8879 was published on 2026-06-03 and last updated on 2026-06-17.

CVE-2026-8879

CVE-2026-8879 is a high-severity vulnerability in Securly with a CVSS 3.x base score of 7.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-829.

Key facts

Severity: High (CVSS 3.x base score 7.5)
EPSS exploit prediction: 0% (29th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-34165
Weakness: CWE-829
Affected product: Securly
Published: 2026-06-03
Last modified: 2026-06-17

Description

Version 3.0.7 of the Securly Chrome Extension dynamically registers content13.min.js as a content script via chrome.scripting.registerContentScripts() at runtime. This script is NOT declared in manifest.json and bypasses Chrome Web Store static security review. It runs on all URLs and immediately hides all page content, creates a full-page overlay, pauses all videos, and only restores content when the service worker confirms the page passes filtering. If Securly's servers are unreachable, pages remain indefinitely hidden.

Frequently asked questions

What is CVE-2026-8879?: Version 3.0.7 of the Securly Chrome Extension dynamically registers content13.min.js as a content script via chrome.scripting.registerContentScripts() at runtime. This script is NOT declared in manifest.json and bypasses Chrome Web Store static security review. It runs on all URLs and immediately hides all page content, creates a full-page overlay, pauses all videos, and only restores content when the service worker confirms the page passes filtering. If Securly's servers are unreachable, pages remain indefinitely hidden.
How severe is CVE-2026-8879?: CVE-2026-8879 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2026-8879 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (29th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-8879?: CVE-2026-8879 affects Securly. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-8879?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
Does CVE-2026-8879 have an EU (EUVD) identifier?: Yes. CVE-2026-8879 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-34165.
When was CVE-2026-8879 published?: CVE-2026-8879 was published on 2026-06-03 and last updated on 2026-06-17.

References

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

Affected products (1)

cpe:2.3:a:securly:securly:3.0.7:*:*:*:*:chrome:*:*

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