CVE-2026-59859Public exploitNetwork attack vector

PHP code execution via unescaped interpolation markers

Published Jul 16, 2026 · Updated Jul 16, 2026

Code injection in Microsoft Kiota 1.29.0 and earlier and 1.30.0 through 1.32.3 allows attackers to execute PHP code. SanitizeDoubleQuote() in Writers/StringExtensions.cs emits schema-derived strings into PHP double-quoted literals without escaping $, so PHP interprets attacker-supplied interpolation expressions when generated clients run. Exploitation requires control of an OpenAPI specification and a developer or pipeline to generate and then execute or deploy the resulting PHP client.

CVSS severity8.7
High
EPSS probability1.38%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Code injection in Microsoft Kiota 1.29.0 and earlier and 1.30.0 through 1.32.3 allows attackers to execute PHP code. SanitizeDoubleQuote() in Writers/StringExtensions.cs emits schema-derived strings into PHP double-quoted literals without escaping $, so PHP interprets attacker-supplied interpolation expressions when generated clients run. Exploitation requires control of an OpenAPI specification and a developer or pipeline to generate and then execute or deploy the resulting PHP client.

The record

CVE
CVE-2026-59859
Published
Jul 16, 2026
Updated
Jul 16, 2026
Vendor
Microsoft
Product
Kiota
Classifications
CWE-94, T1204.002
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jul 16, 2026CVE publishedPublication date reported by the CVE source.
  2. Jul 16, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 1.32.4

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Microsoft · Kiotaversion=< 1.32.4

Published CVSS scores

8.7GitHubCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-94Improper Control of Generation of Code ('Code Injection')
T1204.002User Execution: Malicious File

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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