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PatchSiren cyber security CVE debrief

CVE-2026-77115 Brave CVE debrief

The Brave Popup Builder plugin up to version 0.8.5 reflects UTM query parameters into popup form HTML without escaping them, allowing for potential XSS attacks. This vulnerability could impact web applications using the plugin, as attackers may exploit the reflected UTM query parameters to execute malicious scripts. Defenders should assess exposure and prioritize verification of the plugin version to prevent potential security issues. The CVE record and NVD vulnerability detail page provide information on the vulnerability, but do not provide evidence of exploitation or specific affected versions beyond version 0.8.5 of the Brave Popup Builder plugin.

Vendor
Brave
Product
Popup Builder
CVSS
HIGH 7.1
CISA KEV
Not listed in stored evidence
Original CVE published
2026-08-23
Original CVE updated
2026-10-12
Advisory published
2026-08-23
Advisory updated
2026-10-12

Who should care

Defenders responsible for maintaining and securing web applications using the Brave Popup Builder plugin should assess exposure and prioritize verification of the plugin version.

Why it matters

Defenders should care about CVE-2026-77115 because it involves a potential XSS vulnerability in the Brave Popup Builder plugin, which could lead to security issues if not properly addressed.

  • Potential XSS attacks through reflected UTM query parameters
  • Need to verify plugin version and ensure it is up-to-date
  • Possible impact on web application security

Technical summary

The Brave Popup Builder plugin up to version 0.8.5 reflects UTM query parameters into popup form HTML without escaping them, potentially allowing for XSS attacks. This vulnerability is due to the plugin's failure to properly sanitize user input, which could lead to security issues if not properly addressed. Defenders should prioritize verifying the version of the Brave Popup Builder plugin and ensuring it is up-to-date to prevent potential XSS attacks.

Defensive priority

Defenders should prioritize verifying the version of the Brave Popup Builder plugin and ensuring it is up-to-date to prevent potential XSS attacks.

Recommended defensive actions

  • Verify the version of the Brave Popup Builder plugin and ensure it is up-to-date
  • Escaping UTM query parameters in popup form HTML
  • Monitor for potential XSS attacks

Evidence notes

The CVE record and NVD vulnerability detail page provide information on the vulnerability, but do not provide evidence of exploitation or specific affected versions beyond version 0.8.5 of the Brave Popup Builder plugin.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-77115 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-77115

    CVE Program - Official CVE Program record with source-provided CVE metadata.

  • CVE-2026-77115 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-77115

    NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.

Supplemental references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.