Microsoft Edge zero-day CVE-2026-87491 exploited
CERT-FR warns of multiple Microsoft Edge vulnerabilities, including CVE-2026-87491 which is actively exploited in the wild.
Sourcecert.ssi.gouv.fr — open the original
What to check
- Applies to
- The 21 CVEs named below. Whether you run an affected version is not assessed: check the versions the source lists.
- Exploitation
- CISA lists CVE-2026-87491 as exploited in the wild.
CERT-FR has issued an advisory covering multiple vulnerabilities in Microsoft Edge affecting versions prior to 151.0.4129.107 and 152.0.4191.66. The flaws allow an attacker to bypass security policy controls and trigger other security issues not further specified by the vendor. Microsoft has confirmed that one of the vulnerabilities, CVE-2026-87491, is being actively exploited in the wild, making it the highest priority item in this batch for defenders.
The advisory bundles 20 CVEs disclosed via Microsoft's security bulletin on 11 September 2026, all affecting the Edge browser. No further technical detail on exploitation vectors, affected components, or IOCs is provided by CERT-FR; organizations are directed to Microsoft's official update guide for patch details. Given the active exploitation of CVE-2026-87491 and the widespread deployment of Microsoft Edge, organizations should prioritize patching to the fixed versions without delay.
Mentioned in this report
Source reporting: https://www.cert.ssi.gouv.fr/avis/CERTFR-2026-AVI-1171
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