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Fencer Vulns
critical 9.3

CVE-2026-59864 json

Kiota: Path/URL injection into generated Copilot plugin manifest via x-ai-* extensions

published 2026-07-16 3 mo ago modified 2026-10-24 15 d ago also EUVD-2026-44935 , GHSA-4jwf-m4wg-8p66

cvss
9.3
version 4.0, CNA
cisa kev
Not listed
not in CISA's catalog
epss
1.3%
EPSS 1.3% chance of exploitation in 30 days, percentile 71%
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 plugin add` and `kiota plugin generate` (with `-t APIPlugin`) emitted attacker-controlled static_template.file values from x-ai-adaptive-card and x-ai-capabilities into generated Microsoft 365 Copilot and Teams plugin manifests without path validation, allowing ../, absolute, rooted, UNC, Windows drive, or URI paths in response_semantics.static_template.file to cause path traversal or out-of-package file inclusion when the generated plugin was deployed. This issue is fixed in version 1.29.1 and 1.32.5.

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

CISA SSVC

Exploitation
none
Automatable
yes
Technical impact
total
Assessed
3 mo ago

Exploit prediction

1.33% chance of exploitation in the next 30 days, higher than 71% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 4.0 9.3 CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
CNA 4.0 9.3 CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

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

References

Sources

Fencer Vulns 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.

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