CVE-2026-21535
CVE-2026-21535 is a high-severity vulnerability in Microsoft Teams with a CVSS 3.x base score of 8.2. 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-284.
Key facts
- Severity: High (CVSS 3.x base score 8.2)
- EPSS exploit prediction: 1% (44th percentile)
- Actively exploited: Not listed in CISA KEV
- EU (EUVD) id: EUVD-2026-7572
- Weakness: CWE-284
- Affected product: Microsoft Teams
- Published:
- Last modified:
Description
Improper access control in Microsoft Teams allows an unauthorized attacker to disclose information over a network.
Frequently asked questions
- What is CVE-2026-21535?
- Improper access control in Microsoft Teams allows an unauthorized attacker to disclose information over a network.
- How severe is CVE-2026-21535?
- CVE-2026-21535 has a CVSS 3.x base score of 8.2, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity low, and availability none.
- Is CVE-2026-21535 being actively exploited?
- It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (44th percentile), an estimate of the probability of exploitation in the next 30 days.
- What products are affected by CVE-2026-21535?
- CVE-2026-21535 affects Microsoft Teams. See the affected-products list for the exact vulnerable versions.
- How do I fix CVE-2026-21535?
- Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
- Does CVE-2026-21535 have an EU (EUVD) identifier?
- Yes. CVE-2026-21535 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-7572.
- When was CVE-2026-21535 published?
- CVE-2026-21535 was published on 2026-02-19 and last updated on 2026-06-17.
References
Affected products (1)
- cpe:2.3:a:microsoft:teams:-:*:*:*:*:*:*:*
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