How severe is CVE-2026-83711?

CVE-2026-83711 has a CVSS 3.x base score of 10.0, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability none.

Is CVE-2026-83711 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (46th percentile), an estimate of the probability of exploitation in the next 30 days.

How do I fix CVE-2026-83711?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.

When was CVE-2026-83711 published?

CVE-2026-83711 was published on 2026-09-03 and last updated on 2026-09-08.

CVE-2026-83711

CVE-2026-83711 is a critical-severity vulnerability with a CVSS 3.x base score of 10.0. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-639.

Key facts

Severity: Critical (CVSS 3.x base score 10.0)
EPSS exploit prediction: 1% (46th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-639
Published: 2026-09-03
Last modified: 2026-09-08

Description

Authorization bypass through user-controlled key in Microsoft Azure Active Directory B2C allows an unauthorized attacker to elevate privileges over a network.

Frequently asked questions

What is CVE-2026-83711?: Authorization bypass through user-controlled key in Microsoft Azure Active Directory B2C allows an unauthorized attacker to elevate privileges over a network.
How severe is CVE-2026-83711?: CVE-2026-83711 has a CVSS 3.x base score of 10.0, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability none.
Is CVE-2026-83711 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (46th percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2026-83711?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
When was CVE-2026-83711 published?: CVE-2026-83711 was published on 2026-09-03 and last updated on 2026-09-08.

References

https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-83711

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