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Fencer Intel
high 7.1

CVE-2026-59867 json

Kiota: Generation-time SSRF + remote/local file inclusion via unrestricted $ref

published 4mo ago modified 18d ago also EUVD-2026-44937 , GHSA-rg4h-fpcp-2qm8

cvss
7.1
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
2.4%
EPSS 2.4% chance of exploitation in 30 days, percentile 84%
public exploits
0
none known

Summary

Kiota is an OpenAPI based HTTP Client code generator. Prior to 1.29.1 and 1.32.5, Kiota resolved OpenAPI $ref values by fetching remote http(s) URLs and reading local absolute or out-of-tree file paths, allowing `kiota generate` on an attacker-controlled or attacker-influenced description to perform build-time SSRF, remote file inclusion, and local file inclusion by inlining external schemas such as REMOTE_KIOTA_PROP or Leaked into generated clients. This issue is fixed in version 1.29.1 and 1.32.5 by AllowedExternalOriginsStreamLoader and the --allowed-external-origins option.

Patch / fix

  • nuget Microsoft.OpenApi.Kiota 1.29.1, 1.32.5
  • nuget Microsoft.OpenApi.Kiota.Builder 1.29.1, 1.32.5
  • microsoft kiota 1.29.1, 1.32.5
  • microsoft microsoft.openapi.kiota 1.29.1, 1.32.5
  • microsoft microsoft.openapi.kiota.builder 1.29.1, 1.32.5

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CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
3mo ago

Exploit prediction

2.39% chance of exploitation in the next 30 days, higher than 84% of all scored CVEs (FIRST EPSS, 2026-11-11).

CVSS scores

assigned by version score vector
CNA 3.1 7.1 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:L/A:N
GitHub 3.1 7.1 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:L/A:N

Affected packages

ecosystem package affected fixed in
nuget Microsoft.OpenApi.Kiota
>=1.30.0, <1.32.5
<1.29.1
1.32.5
1.29.1
nuget Microsoft.OpenApi.Kiota.Builder
>=1.30.0, <1.32.5
<1.29.1
1.32.5
1.29.1

Affected products

  • microsoft kiota

Classification

Weakness
  • CWE-22 Improper Limitation of a Pathname to a Restricted Directory
  • CWE-829 Inclusion of Functionality from Untrusted Control Sphere
  • CWE-918 Server-Side Request Forgery

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

The maintainers of microsoft/kiota published their own advisory on GitHub. Reviewed sources take precedence over it.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.