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Not in CISA KEV
HIGH severity

CVE-2026-58281 — Edge Chromium

HIGH

CVE-2026-58281 is a high-severity (CVSS 8.3) Deserialization of Untrusted Data vulnerability in microsoft edge chromium. A fix is available — see the affected versions and patch details below.

Deserialization of untrusted data in Microsoft Edge (Chromium-based) allows an unauthorized attacker to execute code over a network.

Published
Updated
Affected
1 product
Patched
See advisory
Exploits
None indexed
Exploitation data as of Oct 8, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

No confirmed exploitation observed yet

  • A successful exploit gives an attacker total control of the affected component, not partial access.
  • CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.

Exploitation and automatability from CISA’s SSVC triage for CVE-2026-58281.

EPSS Exploitation Probability

via FIRST.org ↗
1.0%probability of exploitation in next 30 days
Lower Risk0.00%
Lower risk than most CVEs60th percentile — riskier than 60% of all scored CVEsHighest risk
0.20%0.62%1.04%1.46%0.7%1.0%1.0%1.0%Aug 26Oct 26Oct 26

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

How urgent is this, really

CVE-2026-58281 by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.

Where this sits among everything scored

Of 385,386 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Counts from FIRST.org, log-scaled.

Description

Deserialization of untrusted data in Microsoft Edge (Chromium-based) allows an unauthorized attacker to execute code over a network.

Affected Products

1 product · 1 configurations
Application
edge chromiummicrosoft
< 150.0.4078.48
range

Detection & mitigation playbook

Vendor / appliance

  1. Detect

    Inventory every microsoft edge chromium deployment and check each version against the affected-products list above.

  2. Fix

    Apply the microsoft edge chromium security patch or hotfix for CVE-2026-58281 on the affected version, following the vendor advisory for your exact build.

  3. Workarounds

    Do not deserialise data from untrusted sources: where the format allows it, restrict deserialisation to an explicit allowlist of expected types, and prefer a data-only format (JSON, Protobuf) over one that can reconstruct arbitrary objects until you can upgrade. Alongside that, restrict the management interface to trusted networks and apply the vendor's recommended configuration mitigations.

Frequently Asked Questions

Deserialization of untrusted data in Microsoft Edge (Chromium-based) allows an unauthorized attacker to execute code over a network.
O3 Security · Runtime Protection

Is CVE-2026-58281 being exploited in your environment?

Detect and block the exploit chain at execution, on systems you cannot patch yet.

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