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CVE-2026-58630: Microsoft Azure App Service For Linux Improper Access Control (CVSS 10)

CVE-2026-58630 is a critical severity improper access control in Microsoft Azure App Service For Linux with a CVSS score of 10. Apply the vendor fix and confirm exposure on internet facing and business critical assets first.

Last updated: Aug 6, 2026

Quick answer

Direct answer

CVE-2026-58630 is a critical severity improper access control in Microsoft Azure App Service For Linux with a CVSS score of 10. Apply the vendor fix and confirm exposure on internet facing and business critical assets first.

Risk scores

CVSS base score
10CRITICAL
EPSS probability
0.86%
Higher than 58 percent of all CVEs
CISA KEV
Not listed
CVSS metricWhat it means
Attack vector (AV:N)Network: reachable remotely
Attack complexity (AC:L)Low complexity
Privileges required (PR:N)No privileges required
User interaction (UI:N)No user interaction
Scope (S:C)Scope changed: impact spreads beyond the component
Confidentiality (C:H)High confidentiality impact
Integrity (I:H)High integrity impact
Availability (A:N)No availability impact

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:N

About Microsoft Azure App Service For Linux

CVE-2026-58630 affects Microsoft Azure App Service For Linux, a product from Microsoft. Before acting, confirm where Microsoft Azure App Service For Linux runs in your estate, who owns it and whether it is reachable from the internet, because exposure decides real risk more than the score alone.

What the flaw is

In plain terms: Improper access control in Azure App Service allows an unauthorized attacker to elevate privileges over a network.

The weakness class is Improper Access Control. The software does not properly restrict who can use a resource.

Based on its CVSS vector, the flaw can be reached over the network, needs no login, and needs no user interaction. Apply the vendor fix and confirm exposure on internet facing and business critical assets first.

Affected versions and timeline

FieldDetail
ProductMicrosoft Azure App Service For Linux
Affected versionsAzure App Service For Linux all listed versions
PublishedJul 24, 2026
Last modifiedAug 6, 2026
Added to CISA KEVNot listed
Assigning CNAsecure@microsoft.com

How to detect it

  • Inventory every instance of Microsoft Azure App Service For Linux and record the running version against the affected range above.
  • Check external attack surface scans for internet facing instances of the component.
  • Review logs on affected systems for unusual requests, errors or new processes around the vulnerable function.
  • Confirm with an authenticated vulnerability scan once your scanner has a check for this CVE.

How to fix it

  • Apply the fixed version of Microsoft Azure App Service For Linux named in the vendor advisory.
  • If patching must wait, restrict network access to the affected service and put it behind authentication or a web application firewall rule.
  • Rescan after the change to prove the exposure is gone, then close the ticket.

CTEM action plan

CTEM stageWhat to do for this CVE
ScopeAdd every business service that depends on Microsoft Azure App Service For Linux to the current CTEM cycle.
DiscoverFind all instances, including shadow and cloud deployments, and record versions and exposure.
PrioritizeRank using EPSS and CVSS together with asset exposure and business impact.
ValidateConfirm the flaw is reachable and exploitable in your environment and that compensating controls work.
MobilizeAssign the fix to the asset owner with a due date matched to the priority, then verify closure.

CWE References

Technical References

Frequently asked questions

CVE-2026-58630 is a critical severity improper access control in Microsoft Azure App Service For Linux with a CVSS score of 10. Apply the vendor fix and confirm exposure on internet facing and business critical assets first.

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