CVE-2026-86439

Exploitation

Assessed, none found. CISA's assessment recorded neither public exploit code nor evidence of exploitation when it was made.

SSVC decision

• ExploitationnoneCISA recorded no public exploit code and no evidence of exploitation.
• AutomatablenoAt least one step from reconnaissance to exploitation cannot be reliably automated.
• Technical ImpacttotalSuccessful exploitation gives total control of the vulnerable component.

CISA publishes the decision points, not a final SSVC decision. The decision also depends on mission and well-being impact, which is a property of your deployment rather than of the vulnerability.

EPSS probability

1.07% probability of exploitation activity in the next 30 days.

EPSS percentile

Equal to or higher than the score of 64.7% of scored records. A rank, not a probability.

NVD base score

8.7 (CVSS v4.0), scored by the NVD independently of the CNA.

NVD CVSS vector

CVSS:4.0/AV:N/AC:L/AT:N/PR:L/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

NVD analysis status

Deferred. NVD last modified this record on 2026-09-08.

Red Hat severity

No Red Hat rating. Red Hat rates the CVEs that affect its products.

Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.

Published

2026-09-07 23:03Z1 MO AGO

Last updated

2026-09-24 14:21Z1 MO AGO

Reserved

2026-09-07

Assigning CNA

VulnCheck

Record state

PUBLISHED

Severity

High (CVSS 8.7)

CNA CVSS vector

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

Weaknesses

• CWE-22Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')Base

Data version

5.2

Document digest

a9d93b556fca7f4d43909955c5bc058f166b994999fa65f7810d23beb4d1f240

• github.comGitHub Security Advisory (GHSA-9gfj-28hw-jchp)https://github.com/knowns-dev/knowns/security/advisories/GHSA-9gfj-28hw-jchpvendor-advisory
• github.comDocStore.Get path join without containment (v0.29.1)https://github.com/knowns-dev/knowns/blob/v0.29.1/internal/storage/doc_store.go#L124-L129technical-description
• github.comMemoryStore.GetInLayer path join without containment (v0.29.1)https://github.com/knowns-dev/knowns/blob/v0.29.1/internal/storage/memory_store.go#L203-L211technical-description
• github.comknowns fix commit 09c5a96fd581https://github.com/knowns-dev/knowns/commit/09c5a96fd5817b941dc86669278c1a17db10ed4epatch
• github.comknowns v0.30.0 Release Noteshttps://github.com/knowns-dev/knowns/releases/tag/v0.30.0release-notes
• www.vulncheck.comVulnCheck Advisory: knowns before 0.30.0 Path Traversal via MCP doc and memory toolshttps://www.vulncheck.com/advisories/knowns-before-0.30.0-path-traversal-via-mcp-doc-and-memory-toolsthird-party-advisory