CVE-2026-58499: EverOS Path Traversal Vulnerability

CVE-2026-58499 Overview

CVE-2026-58499 is a path traversal vulnerability [CWE-22] in EverOS, a memory runtime framework for AI agents. The flaw affects versions prior to 1.0.1 and resides in the POST /api/v1/memory/add ingestion endpoint. The per-message sender_id field was not validated as a path-safe identifier, unlike app_id and project_id. An unauthenticated remote attacker can supply sender_id values containing ../ sequences to write or overwrite Markdown files outside the configured memory root. The vulnerability is fixed in EverOS 1.0.1.

Critical Impact
Unauthenticated attackers can create or overwrite .md files at arbitrary filesystem locations writable by the EverOS server process, enabling integrity compromise and potential code or configuration tampering.

Affected Products

EverOS versions prior to 1.0.1
EverMind-AI EverOS memory runtime framework
Deployments exposing the /api/v1/memory/add endpoint

Discovery Timeline

2026-07-10 - CVE-2026-58499 published to NVD
2026-07-13 - Last updated in NVD database

Technical Details for CVE-2026-58499

Vulnerability Analysis

EverOS is a Markdown-first memory extraction framework that persists agent memory as .md files on the local filesystem. The ingestion endpoint POST /api/v1/memory/add accepts per-message metadata including app_id, project_id, and sender_id. During user-memory extraction, the runtime uses sender_id as owner_id and joins it into the filesystem path used to persist the extracted episode.

While app_id and project_id were validated as path-safe identifiers, sender_id bypassed this control. An attacker submits a request with a sender_id containing ../ traversal sequences, directing writes outside the configured memory root. The endpoint requires no authentication, and the attacker partially influences the file contents through the ingested message payload.

Root Cause

The root cause is missing input validation on the sender_id field. Unlike sibling identifiers, sender_id was passed unfiltered into path construction logic, violating the principle of least trust for user-supplied path components [CWE-22].

Attack Vector

The attack vector is network-based and unauthenticated. An attacker sends a crafted HTTP POST to /api/v1/memory/add with a sender_id such as ../../../etc/target and a message body containing content the server will persist. The runtime writes the resulting .md file at the traversed location under the server process's write permissions.

text

// Security patch reference — EverOS 1.0.1 version bump
[project]
 name = "everos"
-version = "1.0.0"
+version = "1.0.1"
 description = "EverOS — local-first markdown memory framework for AI agents and user chats; lightweight, dev-friendly, small-team"

// Source: https://github.com/EverMind-AI/EverOS/commit/a10cdcd197747f371b7879a32c2cc3f77471e9c2

Detection Methods for CVE-2026-58499

Indicators of Compromise

HTTP requests to /api/v1/memory/add containing ../ or URL-encoded %2e%2e%2f sequences in the sender_id field
Unexpected .md files appearing outside the configured EverOS memory root directory
Modification timestamps on system Markdown files (e.g., README files, documentation) matching EverOS server process activity

Detection Strategies

Inspect application logs for POST /api/v1/memory/add requests with anomalous sender_id values that include path separators or traversal sequences
Monitor filesystem write events by the EverOS process user outside the designated memory storage path
Deploy web application firewall rules to flag path traversal patterns in JSON request bodies targeting EverOS endpoints

Monitoring Recommendations

Enable audit logging on the host filesystem for .md file creation events outside the EverOS memory root
Correlate EverOS API access logs with filesystem telemetry to identify unauthorized write locations
Alert on any unauthenticated ingestion requests originating from untrusted network segments

How to Mitigate CVE-2026-58499

Immediate Actions Required

Upgrade EverOS to version 1.0.1 or later, which validates sender_id as a path-safe identifier
Restrict network exposure of the /api/v1/memory/add endpoint to trusted clients until patching is complete
Audit the filesystem writable by the EverOS server process for unexpected .md files created before the upgrade

Patch Information

The fix is available in EverOS Release v1.0.1. Technical patch details are documented in the GitHub commit a10cdcd and the GitHub Security Advisory GHSA-c795-2g9c-j48m.

Workarounds

Place EverOS behind an authenticating reverse proxy that rejects requests with sender_id values containing /, \, or .. sequences
Run the EverOS process under a restricted user account with write permissions limited to the memory root directory only
Apply mandatory access control (SELinux, AppArmor) profiles that confine EverOS file writes to the intended storage path

bash

# Upgrade EverOS to the patched release
pip install --upgrade everos==1.0.1

# Verify installed version
python -c "import everos; print(everos.__version__)"