# CVE-2026-127276: Linksys EA8100 Web UI cookie httponly flag

Status: published. Published: 2026-11-13. Updated: 2026-11-13.

A vulnerability was identified in Linksys EA8100 1.0.3.216940. Impacted is an unknown function of the component Web UI. Such manipulation leads to cookie without 'httponly' flag. It is possible to launch the attack remotely. This attack is characterized by high complexity. The exploitability is considered difficult. The exploit is publicly available and might be used. The vendor was contacted early about this disclosure but did not respond in any way.

## Remediation

No remediation reported in collected sources

## Affected products and versions

- Linksys / EA8100: 1.0.3.216940 (affected). Source: CNA: VulDB

## Severity and prioritization

- CVSS 4.0: 6.3 (medium); CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:P; source: CNA: VulDB

- CVSS 3.1: 3.7 (low); CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N/E:P/RL:X/RC:C; source: CNA: VulDB

- CVSS 3.0: 3.7 (low); CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N/E:P/RL:X/RC:C; source: CNA: VulDB

- CVSS 2.0: 2.6 (low); AV:N/AC:H/Au:N/C:P/I:N/A:N/E:POC/RL:ND/RC:C; source: CNA: VulDB

- CISA KEV: No listing in collected sources

- EPSS: Not available

- SSVC: exploitation poc; automatable no; technical impact partial; source ADP: CISA-ADP

- Weaknesses: CWE-1004, CWE-732

## Exploit evidence

- exploit: https://github.com/geo-chen/oss/blob/main/Linksys.md#finding-4-admin-credential-stored-in-a-non-httponly-cookie-admin-auth (CNA: VulDB)

## References

- https://vuldb.com/vuln/436431 (CNA: VulDB; vdb-entry)

- https://vuldb.com/vuln/436431/cti (CNA: VulDB; signature, permissions-required)

- https://vuldb.com/cve/CVE-2026-127276 (CNA: VulDB; third-party-advisory)

- https://vuldb.com/submit/1040998 (CNA: VulDB; third-party-advisory)

- https://github.com/geo-chen/oss/blob/main/Linksys.md#finding-4-admin-credential-stored-in-a-non-httponly-cookie-admin-auth (CNA: VulDB; exploit)

- https://www.linksys.com/ (CNA: VulDB; product)

## Provenance

- CNA: VulDB: https://www.cve.org/CVERecord?id=CVE-2026-127276; retrieved 2026-11-13; source updated 2026-11-13

Revision: 7ebfef02a7c6d38245afaf9511ca708df40297d716f11e567881fddbd87a5f0d

Canonical: https://y2.dev/cve/CVE-2026-127276

## Agent and API access

Public CVE pages, Markdown, and JSON are free to read without an account or API key.

- Public catalog: https://y2.dev/cve/index.json. Follow nextCursor with the same search, filters, sort, and limit (1–100). A null cursor marks the end.

- WebMCP: search_cve_disclosures, get_cve_disclosure, get_cve_page_markdown, get_y2_cve_access. Available in compatible browsers.

- Cyber API: https://api.y2.dev/api/v2/cyber/cves and https://api.y2.dev/api/v2/cyber/cves/{cveId}.

- Y2 Pro or Elite: create a workspace API key with the intel:cyber scope and send Authorization: Bearer <Y2_API_KEY>. Setup: https://y2.dev/docs/api/create-key.

- x402: Pay per request without an account or API key. Omit Authorization, read the HTTP 402 PAYMENT-REQUIRED challenge, validate its current requirements, and retry with PAYMENT-SIGNATURE through an authorized payment client. These browser tools never make payments. Guide: https://y2.dev/docs/api/x402.

- OpenAPI: https://y2.dev/api/openapi.yaml. Agent access metadata: https://y2.dev/cve/agent.json.

Collected public records only. Check source status for coverage and freshness.