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mistral.rs EUVDEUVD-2026-96924

| CVE-2026-108759 HIGH
Improper Link Resolution Before File Access (CWE-59)
2026-10-11 VulnCheck GHSA-fjjm-5mgr-r8vp
7.6
CVSS 4.0 · Vendor: VulnCheck
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Attack ChainAIDerived

Hypothetical attack flow derived from CVE metadata – not a confirmed exploit chain

  1. Access
    Obtain sandboxed code execution via agent/prompt injection
  2. Delivery
    Create symlink named as output or input path
  3. Exploit
    Sandbox follows symlink on file operation
  4. Execution
    Read or overwrite host files as server process
  5. Impact
    Exfiltrate secrets or tamper with data

Vulnerability Assessment

Weakness
CWE
OWASP Top 10:2025
A01:2025 - Broken Access Control
ASVS 5.0
V5 - File Handling Symlink resolution safety
Exploitation Conditions

Requires that the mistralrs-code-exec sandboxed code-execution feature is enabled and reachable, and that the attacker can submit or influence shell code within the sandbox (directly or through a prompt-injected agent) - consistent with PR:L, meaning some session/agent access is needed rather than fully anonymous access. The concrete trigger is the ability to name a symlink as an output path or to reuse a session whose input path points to a symlink (the AT:P attack requirement); mistralrs-code-exec then follows the symlink during file read/write operations. Limiting factors: only versions 0.9.0 through 0.9.4 are affected, the code-exec feature must be in use, the attacker must control symlink naming or session reuse, and impact is bounded by the server process's filesystem permissions. Deployments that do not expose the code-execution sandbox to untrusted input are not realistically exploitable.

Impact

This is a moderate-priority, context-dependent vulnerability rather than a mass-exploitation threat. The CVSS 4.0 vector (AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H) scores 7.6 (High) and indicates network reachability with low privileges and low complexity, but critically includes AT:P - an attack requirement - reflecting that exploitation depends on the attacker controlling symlink names or reusing sessions with symlinked paths, and on the code-exec sandbox feature being in use. Exploitation status is 'no public exploit identified at time of analysis': the CVE is not on CISA KEV and no proof-of-concept exploit code is flagged in the input, though a detailed technical write-up exists on hackmd and the vendor advisory (VulnCheck) pinpoints the vulnerable source lines, which lowers the bar for a skilled attacker to reproduce it. EPSS and SSVC data were not provided, so probabilistic exploitation likelihood cannot be quantified from this input - treat the likelihood as unknown. The real risk is concentrated in AI-agent deployments where untrusted or prompt-injected content can reach the code-execution sandbox; in those settings the sandbox escape is genuinely serious (host file read/overwrite with server-process permissions), but for deployments that do not expose mistralrs-code-exec to untrusted input the practical risk is low. Net: a legitimately high-impact flaw gated by meaningful preconditions, not a drive-by network exploit.

Exploit ScenarioDerived

An attacker interacting with an LLM agent backed by mistral.rs - or injecting malicious instructions via prompt injection - causes sandboxed shell code to create a symlink and name it as an output path (or reuses a session with a symlinked input path). When mistralrs-code-exec follows the symlink, it reads or overwrites files outside the intended sandbox with the server process's permissions, enabling data theft or tampering. No public exploit code is identified, but a detailed technical write-up and the exact vulnerable source lines are publicly referenced.

This Week Schedule remediation this week. Why: HIGH severity (CVSS 7.0-8.9).
No patch listed yet 0.3% exploitation probability (EPSS)

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AnalysisAIv1 – Oct 11, 2026

Improper link following in mistral.rs 0.9.0 through 0.9.4 allows code running in the mistralrs-code-exec sandbox to read and overwrite files outside the intended sandbox by using symlinks with the server process's filesystem permissions. The flaw requires the code-execution feature to be enabled and reachable, low-level session or agent access (PR:L), and the ability to name a symlink as an output or reuse a session whose input path is a symlink (AT:P), making it a moderate-priority, context-dependent issue rather than a mass-exploitation threat; no public exploit identified at time of analysis.

RemediationAI

No vendor-released patch identified at time of analysis; check the mistral.rs GitHub repository and VulnCheck advisory for an updated release or commit. Until a fix is available, disable mistralrs-code-exec or do not expose its sandboxed code-execution feature to untrusted or model-generated input, especially from prompt-injected agents. If the feature must remain enabled, run the mistral.rs server under a dedicated low-privilege account, restrict its filesystem view with container/chroot/read-only mounts so symlink targets outside the sandbox are inaccessible, block the code-exec endpoint from untrusted networks, and avoid session reuse with symlinked input paths or symlink output names in tooling. These mitigations reduce exposure but do not fully correct the underlying link-following flaw and may break legitimate file operations; monitor the referenced advisory and code paths for patch status.

Affected VersionsENISA

Mistral.rs 0.9.0 ≤0.9.4

Affected Packages

euvd mistral_rs no fix

Source: OSV (Open Source Vulnerabilities)

Affects your stack

Affects 1 package in euvd

Checking this CVE against your own stacks and servers is part of the Basic plan and up.

Technical ContextAI · show details

mistral.rs is a Rust-based inference server, and its mistralrs-code-exec component provides sandboxed shell code execution. CVE-2026-108759 is a CWE-59 improper link resolution issue in that component: referenced code in mistralrs-code-exec/src/files.rs (lines 241-254) and source mount handling in src/mount.rs (lines 30-50) follows symlinks during file read/write or mount operations rather than rejecting them. The supplied CVSS 4.0 vector is CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N, while the independent assessment maps the issue to CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:N. Exploitation requires the code-exec sandbox to be enabled and reachable, low-level session/agent access, and an attacker-controlled symlink as an output name or reused session input path; impact is bounded by the permissions of the mistral.rs server process. CPE data identifies ericlbuehler:mistral.rs, with affected releases described as 0.9.0 through 0.9.4.

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Severity by source

Vendor (VulnCheck) PRIMARY 7.6 HIGH
CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N
vuln.today AI 8.2 HIGH

Network-reachable code-exec feature (AV:N) but exploitation requires controlling symlink names/session reuse (AC:H) with low-privilege sandbox access (PR:L); sandbox escape to host files is a scope change (S:C) with high confidentiality and integrity impact.

3.1 AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:N
4.0 AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N

Primary rating from Vendor (VulnCheck).

CVSS VectorVendor: VulnCheck

Attack Vector
Network
Attack Complexity
Low
Attack Requirements
Present
Privileges Required
Low
User Interaction
None
Vulnerable system: Confidentiality
High
Vulnerable system: Integrity
High
Vulnerable system: Availability
None
Subsequent system: Confidentiality
None
Subsequent system: Integrity
None
Subsequent system: Availability
None

DescriptionCVE.org

mistral.rs 0.9.0 through 0.9.4 contains a link following vulnerability in mistralrs-code-exec that allows sandboxed shell code to read and overwrite files outside the sandbox via symlinks. Attackers or prompt-injected agents can name symlinks as outputs or reuse sessions with symlinked input paths to access files with the server process's permissions.

Executive ViewAI

Why It Matters

Mistral.rs versions 0.9.0 through 0.9.4 contain a high-severity improper link-following flaw in the mistralrs-code-exec sandbox that could allow code running in the sandbox to read or overwrite files outside its intended boundary using the server process's filesystem permissions. This affects organizations that enable and expose the code-execution feature to low-level session or agent access, creating potential data confidentiality and integrity risks, though exploitation is context-dependent and no public exploit identified at time of analysis. Leadership should care because unpatched exposure could lead to unauthorized host file access, and mitigation requires either disabling the feature or tightening access until a vendor fix arrives.

Business Impact: High
Compensating Controls

No vendor-released patch identified at time of analysis. Disable the code-execution feature if not required; restrict reachability to trusted sessions/agents; enforce least privilege on the server process; block or sanitize symlinked input/output paths; isolate the service in a container/VM with restricted host mounts; monitor for unauthorized file access. Apply vendor patch when released.

Threat Intelligence Overview

EPSS Score
0.3%
Top 77% exploitable
Prevalence
Low
niche open-source Rust LLM inference engine, limited production footprint
Social Media
1
Sightings
Data Quality
5 sources
Confidence: Medium

How this decision was reached

The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.

SignalValue
Severity HIGH
CISA KEV No
Public POC No
EPSS 0.3%
Patch available No
Active threat No
Deciding rule
HIGH severity (CVSS 7.0-8.9)
What every action level means
Emergency Immediate action required. Criteria: CRITICAL + in CISA KEV (actively exploited) without patch, OR CRITICAL + EPSS > 30% without patch, OR CRITICAL + active threat signals without patch.
Act Now Prioritize within 24-48h. Criteria: in KEV with patch available, OR CRITICAL + public POC, OR HIGH + EPSS > 10%, OR CRITICAL + active threat, OR any CRITICAL severity.
This Week Schedule remediation this week. Criteria: HIGH severity (CVSS 7.0-8.9). Patch within normal change window.
This Month Plan within 30 days. Criteria: MEDIUM severity (CVSS 4.0-6.9), lower exploitation probability. Include in regular patch cycle.
Monitor Track and reassess. Criteria: LOW severity (CVSS 0.1-3.9), minimal exploitation risk. No immediate action needed.

SSVC AssessmentENISA

SSVC Decision· derived
Scheduled
Exploitation· derived
None
System Exposure· derived
Open
Automatable· derived
No
Human Impact
High

Priority Score

38
Low Medium High Critical
KEV: 0
EPSS: 0
CVSS: +38
PoC: 0
Weaponized: 0
Threat intel: 0
Gov advisory: 0

Attack Technique

Code Injection CRITICAL

Code injection occurs when an application accepts user input and passes it directly into a language interpreter or evaluator without proper sanitization.

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