CVE-2026-55945: Microsoft Edge (Chromium-based) Information Disclosure Vulnerability

mediumCVSS 4.2CVE-2026-55945

Concurrent execution using shared resource with improper synchronization ('race condition') in Microsoft Edge (Chromium-based) allows an authorized attacker to disclose information locally.

CSIRTS triage

vendor: Microsoft product: Edge (Chromium-based)Information disclosureOther

What: Concurrent execution with improper synchronization allows an authorized attacker to disclose information locally.
Who is affected: Users of Microsoft Edge (Chromium-based) are affected.
Urgency: Remediation is medium urgency due to the potential for information disclosure.
Action: Update to the latest version of Microsoft Edge to mitigate this vulnerability.

AI-assisted analysis generated from the source advisory — verify against the original.

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Details

Source: Microsoft Security Response Center (INTL · vendor-psirt · site)
Severity: medium — CVSS 4.2
Published: 2026-07-02
Exploitation: Not in CISA KEV at last sync

Original advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-55945

Exploitation outlook

EPSS (FIRST.org) estimates each CVE’s probability of exploitation in the next 30 days — here is the CSIRTS.com read on those numbers.

Low exploitation riskCVE-2026-559450.14% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 4% of all scored CVEs.

Referenced CVEs

CVE	CSIRTS overview	External
CVE-2026-55945	coverage & exploitation status	NVD · CVE.org

Same CVEs, other sources

How other CERTs, PSIRTs and databases cover the vulnerabilities in this advisory.

Recent advisories for Microsoft Edge

A cluster of recent advisories against the same product widens the attack surface — attackers routinely chain freshly published CVEs on one product, so review these together.

unknownMicrosoft Edge security advisory (AV26-682)cccs · 2026-07-10
high[NEW] [high] Microsoft Edge: Multiple vulnerabilitiescert-bund · 2026-07-09
unknownVulnerability in Microsoft Edge (July 09, 2026)cert-fr-avis · 2026-07-09
highCVE-2026-58525: Improper access control in Microsoft Edge (Chromium-based) allows an unauthorized attacker to …nvd · 2026-07-08
unknownMultiple vulnerabilities in Microsoft Edge (July 7, 2026)cert-fr-avis · 2026-07-07
unknownMicrosoft Edge security advisory (AV26-659)cccs · 2026-07-06