CVE-2026-66318: Origin validation error in Microsoft Edge (Chromium-based) allows an unauthorized attacker to disclose informa

Q: How do I fix CVE-2026-66318?

edge chromium: upgrade to 151.0.4129.59. Exact commands for each OS are on this page.

Q: Is CVE-2026-66318 being exploited?

CVE-2026-66318 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2026-66318 affect?

CVE-2026-66318 affects edge chromium. Severity is high (CVSS 8.1). Origin validation error in Microsoft Edge (Chromium-based) allows an unauthorized attacker to disclose information over a network.

Q: How urgent is CVE-2026-66318?

Priority 41/100. High severity; On your watchlist

This month

HIGH 8.1WATCHLISTUPGRADE

CVE-2026-66318 is a high-severity flaw (CVSS 8.1) affecting edge chromium. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

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

Why this priority

High severity
On your watchlist

A fixed release or distro patch exists.

Risk facts

CVSS score	8.1 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	Required
EPSS exploit chance	0.4% (top 71%)
CISA exploited list	No
Weakness	CWE-346
Published	2026-08-04
Last modified	2026-10-23

Publisher (CNA): Microsoft Corporation · Vendor: microsoft

Last updated 2026-10-23 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-08-04 00:17 UTCPublished CVE record published
2026-10-23 23:10 UTCUpdated Record last modified

microsoft edge chromium UPGRADE

Affected: < 151.0.4129.59

Fixed in: 151.0.4129.59

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy edge-chromium || rpm -q edge-chromium || edge-chromium --version

2. UPGRADE to 151.0.4129.59 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade edge-chromium

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade edge-chromium

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

Exact fixes by distribution

Fedora 46 · kwin-zones · FIXED · 1.0.13-1.fc46 · FEDORA-2026-95888f332b · source

sudo dnf upgrade --advisory=FEDORA-2026-95888f332b

Fedora ELN · nginx-mod-brotli · FIXED · 1.0.0~rc-16.eln159 · FEDORA-2026-501a6a8273 · source

sudo dnf upgrade --advisory=FEDORA-2026-501a6a8273

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-66318?

edge chromium: upgrade to 151.0.4129.59. Exact commands for each OS are on this page.

Is CVE-2026-66318 being exploited?

CVE-2026-66318 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-66318 affect?

CVE-2026-66318 affects edge chromium. Severity is high (CVSS 8.1). Origin validation error in Microsoft Edge (Chromium-based) allows an unauthorized attacker to disclose information over a network.

How urgent is CVE-2026-66318?

Priority 41/100. High severity; On your watchlist

Software pages

Microsoft Edge vulnerabilities · Chromium vulnerabilities

Related CVEs

CVE-2026-70339 MEDIUM 5.4 UPGRADE Access of resource using incompatible type ('type confusion') in Microsoft Edge (Chromium-based) allows an una
CVE-2026-57990 HIGH 7.4 MITIGATE Files or directories accessible to external parties in Microsoft Edge (Chromium-based) allows an unauthorized
CVE-2026-57989 HIGH 7.4 UPGRADE Origin validation error in Microsoft Edge (Chromium-based) allows an unauthorized attacker to disclose informa
CVE-2026-57978 MEDIUM 5.4 UPGRADE Origin validation error in Microsoft Edge (Chromium-based) allows an unauthorized attacker to perform spoofing
CVE-2026-66321 HIGH 7.4 UPGRADE Access of resource using incompatible type ('type confusion') in Microsoft Edge (Chromium-based) allows an una

References

← Back to latest CVEs