VulnerabilityAnalyzed
CVE-2026-21531
Deserialization of untrusted data in Azure SDK allows an unauthorized attacker to execute code over a network.
CRITICAL 9.8EPSS 2.58%
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (2.58%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
Deserialization of untrusted data in Azure SDK allows an unauthorized attacker to execute code over a network.
- CVSS 3.1
- 9.8 CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- EPSS
- 2.58% probability · 85th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-502
- Affected
- microsoft/azure conversation authoring client library
- Source
- secure@microsoft.com
EPSS 2.6% since 26 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
References
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.