# CVE-2026-57978 — Microsoft Edge (Chromium-based)

> As of 2026-07-27, CVE-2026-57978 is a MEDIUM-severity vulnerability in Microsoft Edge (Chromium-based), CVSS v3.1 5.4. No Threadlinqs-tracked threat campaign has been attributed to CVE-2026-57978 as of 2026-07-27; the identifier is re-checked against the Threadlinqs threat corpus on every daily ingest.

**Last updated:** 2026-07-27

## What is CVE-2026-57978?

Origin validation error in Microsoft Edge (Chromium-based) allows an unauthorized attacker to perform spoofing over a network.

The record classifies CVE-2026-57978 under weakness class [CWE-346](https://intel.threadlinqs.com/cwe/CWE-346). Its CVSS v3 base vector states that the flaw is reachable remotely over the network, needs no prior authentication, needs a user to take an action first. 1 affected-product entry is recorded, across 1 vendor, listed below. The identifier was first published 71 days ago.

## Severity and exploitation probability

- **CVSS v3.1 base score:** 5.4 — MEDIUM (`CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N/E:U/RL:O/RC:C`)
- **CISA KEV:** Not listed in the CISA Known Exploited Vulnerabilities catalog
- **Threadlinqs priority:** 2.7/10 — a Threadlinqs composite of the CVSS base score, the EPSS percentile and public exploit availability
- **Published:** 2026-07-26, last modified 2026-07-27

## Is CVE-2026-57978 being exploited?

It currently carries a trending score of 30 in the Threadlinqs vulnerability feed.

## Affected products and versions

- [Microsoft](https://intel.threadlinqs.com/vendors/microsoft): Edge (Chromium-based)

## How to fix CVE-2026-57978

No vendor patch reference has been recorded for CVE-2026-57978 in the tracked sources. Follow the references below for a fix, and treat the products listed above as exposed until the vendor states otherwise.

## Threat activity tracking CVE-2026-57978

No threat campaign in the Threadlinqs corpus currently references CVE-2026-57978, in its CVE list or as an indicator. The linkage is recomputed from the live corpus on every daily ingest, so this section fills in as soon as a tracked campaign cites the identifier.

## Sources

Enriched from CVE.org, NVD. Last verified by Threadlinqs on 2026-07-27. This product uses the NVD API but is not endorsed or certified by the NVD.

**Vendor advisory and patch**

- [msrc.microsoft.com — vendor advisory](https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-57978)

Canonical: https://intel.threadlinqs.com/cve/CVE-2026-57978
Full detection coverage and IOCs for threats exploiting CVE-2026-57978 via the Threadlinqs MCP server (Purple tier): https://intel.threadlinqs.com/mcp