Security readout for executives and security teams
Plain-English summary
CVE-2026-59864 affects Microsoft Kiota before 1.32.5. A malicious or untrusted OpenAPI description could cause generated Microsoft 365 Copilot or Teams plugin manifests to reference files outside the intended plugin package. That can create serious deployment risk if teams generate and publish plugins from attacker-controlled API descriptions.
Executive priority
Prioritize remediation for teams building or deploying Microsoft 365 Copilot and Teams plugins. The business risk is highest where plugin generation is automated or based on external OpenAPI files. Upgrade and regenerate before further deployment.
Technical view
Kiota plugin generation for APIPlugin accepted attacker-controlled static_template.file values from x-ai-adaptive-card and x-ai-capabilities without path validation. The sources identify traversal, absolute, rooted, UNC, Windows drive, and URI paths as unsafe. The issue is fixed in Kiota 1.32.5.
Likely exposure
Exposure is most likely in developer, CI, or platform teams using kiota plugin add or kiota plugin generate -t APIPlugin with Kiota versions before 1.32.5, especially when OpenAPI documents come from third parties or less-trusted sources.
Exploitation context
The source bundle does not show CISA KEV listing or cited evidence of active exploitation. Practical abuse requires influence over the OpenAPI extensions used during plugin generation and a path that leads to deployment of the generated Copilot or Teams plugin.
Researcher notes
Mapped weaknesses are CWE-22 and CWE-829. The affected product is Microsoft Kiota before 1.32.5. The source bundle provides no CPEs and no active exploitation evidence. Analysis should stay focused on generated manifest path handling, not broader Copilot or Teams platform claims.
Mitigation direction
- Upgrade Kiota to version 1.32.5 or later.
- Regenerate affected Copilot and Teams plugin manifests after upgrading.
- Audit OpenAPI x-ai-adaptive-card and x-ai-capabilities extensions for unsafe file paths.
- Review generated manifests for response_semantics.static_template.file entries outside the plugin package.
- Avoid generating deployable plugins from untrusted OpenAPI descriptions without review.
- Follow Microsoft Kiota advisory and release guidance.
Validation and detection
- Inventory Kiota versions used by developers and CI pipelines.
- Identify uses of kiota plugin add and plugin generate with APIPlugin output.
- Inspect generated manifests for traversal, absolute, UNC, drive, rooted, or URI paths.
- Review deployed plugin packages generated before Kiota 1.32.5.
- Confirm regenerated manifests no longer preserve unsafe static_template.file paths.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-22: File access and web shell behavior lookup
File traversal and upload weaknesses can lead teams to review file, web shell, execution, and collection telemetry. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCWE-829: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupFile access behavior lookup
The CVE wording references file access or upload behavior, so file telemetry and web shell review may help. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2026-59864 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- Critical
- CVSS
- 9.3 (4.0)
- Known Exploited
- No
- Published
Vector: 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 and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
SSVC decision data
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
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——GitHub_MVulnerability scoring details
Base CVSS 4.0 score
9.3CriticalVector: 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
Vulnerability timeline
Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.
- CVE reservedCVE Program
The CVE ID was reserved by the assigning CNA.
- CVE publishedCVE Program
The CVE record was published.
- CVE updatedCVE Program
The CVE record metadata indicates this as the latest update time.
ADP provider summaries
Source materials
- CVE List V5 sourceCVE List V5
- https://github.com/microsoft/kiota/security/advisories/GHSA-4jwf-m4wg-8p66CVE reference, GitHub_M · x_refsource_CONFIRM
- https://github.com/microsoft/kiota/pull/7892CVE reference, GitHub_M · x_refsource_MISC
- https://github.com/microsoft/kiota/commit/9a185994a4e549b7bba3cc2beffb9736aa902e79CVE reference, GitHub_M · x_refsource_MISC
- https://github.com/microsoft/kiota/releases/tag/v1.32.5CVE reference, GitHub_M · x_refsource_MISC
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal') represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.
Inclusion of Functionality from Untrusted Control Sphere
Inclusion of Functionality from Untrusted Control Sphere represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.