# CVE-2026-88078: CVE-2026-88078

Status: published. Published: 2026-10-29. Updated: 2026-11-03.

Improper verification of cryptographic signature in Microsoft Edge (Chromium-based) allows an unauthorized attacker to perform spoofing over a network.

## Remediation

- fix: The reporting source identifies this reference as a patch. Check the advisory for affected versions and supported release branches. (source: secure@microsoft.com) — https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-88078

## Affected products and versions

- microsoft / edge_chromium: < 156.0.4314.42 (affected, custom). Source: NVD

## NVD configuration conditions

Affected CPE matches depend on the following AND/OR and negation conditions:

```json
[
  {
    "negate": false,
    "nodes": [
      {
        "cpeMatch": [
          {
            "criteria": "cpe:2.3:a:microsoft:edge_chromium:*:*:*:*:*:*:*:*",
            "versionEndExcluding": "156.0.4314.42",
            "vulnerable": true
          }
        ],
        "negate": false,
        "operator": "OR"
      }
    ],
    "operator": "OR"
  }
]
```

## Severity and prioritization

- CVSS 3.1: 4.3 (medium); CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N; source: NVD: secure@microsoft.com

- CISA KEV: No listing in collected sources

- EPSS: Not available

- SSVC: exploitation none; automatable no; technical impact partial; source NVD SSVC: 134c704f-9b21-4f2e-91b3-4a467353bcc0

- Weaknesses: CWE-347

## Exploit evidence

No exploit evidence in collected sources. This is not proof of no exploitation.

## References

- https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-88078 (secure@microsoft.com; Patch, Vendor Advisory)

## Provenance

- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-88078; retrieved 2026-11-03; source updated 2026-11-03

Revision: 0171f1b773d643fbab67ab725aa599d4c7b32824f648e8443e7471b91e59f915

Canonical: https://y2.dev/cve/CVE-2026-88078

## Agent and API access

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- 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.

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