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PatchSiren cyber security CVE debrief

CVE-2026-41448 AdguardTeam CVE debrief

CVE-2026-41448 is a critical authentication bypass vulnerability in AdGuard Home when started with the --glinet flag. This vulnerability allows unauthenticated attackers to gain full admin access by supplying a path traversal sequence in the Admin-Token cookie, exploiting unsanitized string concatenation in the token file path construction within the authglinet middleware. Attackers can craft a request with a traversal payload in the Admin-Token header to redirect file reads to arbitrary paths.

Vendor
AdguardTeam
Product
AdGuardHome
CVSS
CRITICAL 9.2
CISA KEV
Not listed in stored evidence
Original CVE published
2026-06-08
Original CVE updated
2026-07-23
Advisory published
2026-06-08
Advisory updated
2026-07-23

Who should care

Users of AdGuard Home with the --glinet flag enabled should be aware of this vulnerability and take immediate action to mitigate the risk.

Technical summary

The vulnerability exists in the authglinet middleware of AdGuard Home when started with the --glinet flag. The middleware improperly handles the Admin-Token cookie, allowing an attacker to bypass authentication by providing a path traversal sequence. This can lead to full admin access for unauthenticated attackers.

Defensive priority

High

Recommended defensive actions

  • Apply the patch from AdGuard Home version v0.107.77 (see resourceLinkAnnotations 'ref-4')
  • Review and update AdGuard Home configurations to ensure the --glinet flag is properly secured
  • Monitor for suspicious activity and implement additional security measures to detect potential exploitation attempts

Evidence notes

The CVE-2026-41448 record was obtained from the official CVE.org database (see resourceLinkAnnotations 'cve-org'). Additional information was sourced from NVD (see resourceLinkAnnotations 'nvd') and Vulncheck (see resourceLinkAnnotations 'ref-5').

Sources and references

Verified primary and authoritative sources

  • CVE-2026-41448 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-41448

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

  • CVE-2026-41448 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-41448

    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.