CVE-2026-115477 — obsidian-tc: Declined human-in-the-loop confirmations can permit destructive calls over HTTP
obsidian-tc is a governed, agent-ready Model Context Protocol server for Obsidian vaults. From 1.13.0 until 1.31.4, on a Streamable HTTP deployment with `auth.jwtSecret` configured and a 2026-07-28-era client declaring `elicitation.form` support, a dispatch-gated tool call offered an `inputRequired` confirmation could still complete after the human declined or cancelled, or the elicitation response was omitted or malformed, provided the client echoed the validly bound `requestState` on resubmission. The server trusted an authentic, call-bound state as proof of approval even though that state was minted before the `elicitation/create` leg was asked and proved only that the resubmission belonged to the same call. A client behaving incorrectly or under an attacker's control could therefore execute dispatch-gated destructive vault operations without the human's approval, while still requiring the caller's ordinary tool permissions. Only tools marked `destructive: true` or requiring a scope with a human-in-the-loop floor were reachable through this bypass. The sixteen handler-side conditionally gated tools, including `write_note` overwrite and `move_note`, did not read elicitation state on the modern wire and let neither approval nor decline through that path. Affected deployments using stdio or leaving `auth.jwtSecret` unset instead used the CLI `elicit_token` fallback and did not offer this `requestState` round trip. The fix does not prevent a malicious client from reporting a fabricated approval, because the server cannot verify that the client displayed the form or that a human saw it. This issue is fixed in version 1.31.4.
Who exploits it and how urgent it is
A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.
How the score was calculated
- EPSS 0.4% (30-day exploitation probability)+4
- Technical severity (high)+6
- CISA SSVC: exploitation "poc"+5
The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).
Triage
Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.
CISA SSVC assessment CISA
Three decision points CISA publishes for the CVEs it assesses (SSVC 2.0.3). A stakeholder decision, not a severity score.
Remediation
Fixes and mitigations documented by the sources — linked to the original advisory.
- Npm Obsidian-tc: fixed in version 1.31.4 — github.com (GitHub Security Advisories)
First 24 hours
Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.
- Identify exposed assets running the affected vendor/product/version combinations (The-40-Thieves Obsidian-tc, Npm Obsidian-tc).
- Apply the fixed version or the patch documented under Remediation.
- Search available logs for exploit probes matching the vulnerability class (access control), errors and authentication anomalies.
Affected scope
Vendor, product and versions as the sources word them.
| Vendor | Product | Versions | Status | Source |
|---|---|---|---|---|
| The-40-Thieves | Obsidian-tc | version >= 1.13.0, < 1.31.4 | Vulnerable | CVE Program (cve.org) e CISA ADP |
| Npm | Obsidian-tc | ≥ 1.13.0 and ≤ 1.31.3 | Vulnerable | GitHub Security Advisories |
Attack characteristics
The CVSS vector, decoded. It describes the attack, not your exposure to it.
Every base score collected
Sources score independently and may disagree; each row says who scored it and under which version.
| Score | Version | Severity | Expl. | Impact | Scored by |
|---|---|---|---|---|---|
| 7.1 | CVSS 4.0 | High | — | — | security-advisories@github.com via NIST National Vulnerability Database |
| 7.1 | CVSS 4.0 | High | — | — | GitHub_M via CVE Program (cve.org) e CISA ADP |
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:H/VA:L/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 (score shown at the top: security-advisories@github.com) Weakness MITRE
Weakness class according to MITRE’s CWE catalog.
EPSS over time FIRST
Oct 24, 2026 → Oct 30, 2026 · 7 reading(s) · max 0.50%
Detection
Read off the CVSS vector and the weakness class. Starting points, not tested rules.
- Prioritize edge telemetry for the network-reachable component (proxy, WAF, IDS/IPS).
- Audit administrative actions and access to resources outside each user’s normal pattern.
Timeline
What happened to this CVE, newest first.
- 2026
- Fix documented
- Affected products added · npm/obsidian-tc
- SSVC assessment updated
- Affected products added · the-40-thieves/obsidian-tc
- Record published
- CVSS changed · 7.1
- Source status changed · → Deferred
- Record created in this database
- CVE published
Source activity
Repeated readings are counted rather than listed.
- 2× References added · Oct 23, 2026 – Oct 29, 2026
- 1× Official description updated · Oct 23, 2026 – Oct 23, 2026
References
8 on the record
- github.com/The-40-Thieves/obsidian-tc/blob/v1.31.4/CHANGELOG.md
- github.com/The-40-Thieves/obsidian-tc/security/advisories/GHSA-737x-cwfr-5vvc
- github.com/advisories/GHSA-737x-cwfr-5vvc
- github.com/The-40-Thieves/obsidian-tc/commit/101c91c656e2c2b88bcf3696a5da035f8c0
- github.com/The-40-Thieves/obsidian-tc/pull/969
- github.com/The-40-Thieves/obsidian-tc/releases/tag/v1.31.4
- github.com/The-40-Thieves/obsidian-tc/issues/967
- nvd.nist.gov/vuln/detail/cve-2026-115477
Elsewhere on this site
Related CVEs (same products)
- High CVE-2026-115478 obsidian-tc: Memory-lifecycle tools overwrite unowned notes or partially commit lifecycle changes 7d
- Medium CVE-2026-77361 obsidian-tc symlink path mismatch bypasses read ACL restrictions 17d
- Medium CVE-2026-77362 obsidian-tc bridge tools expose data outside the read ACL 17d
- High CVE-2026-77363 obsidian-tc Streamable HTTP transport permits cross-origin loopback vault access 18d
- Critical CVE-2026-77366 obsidian-tc tokens can access arbitrary configured vaults 18d
- Medium CVE-2026-77364 obsidian-tc fail-open default ACL exposes Obsidian control-directory secrets 18d
Not in any source we poll
Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.
- No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
- No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
- No exploit packet captures, log samples, or incident case IDs supplied.
Answered from this record
Text assembled only from the fields above — no additional claims.
What should defenders know first?
CVE-2026-115477 is "obsidian-tc: Declined human-in-the-loop confirmations can permit destructive calls over HTTP", rated High. It affects Obsidian-tc (The-40-Thieves); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 7.1 describes technical severity. EPSS 0.35% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.
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