---
id: "CVE-2026-91483"
kind: "vulnerability"
aliases: ["CVE-2026-91483"]
title: "Oracle Outside In: local flaw lets a logged-in attacker take over the product"
severity: "high"
cvss: 7.8
epss: 0.00288
exploited: false
status: "open"
category: "package"
products: []
ecosystems: []
tags: ["fusion-middleware", "on-prem", "oracle", "outside-in", "package"]
not_affected_if: ["outside-in-not-installed"]
published_at: "2026-10-20T22:20:51+00:00"
first_seen_at: "2026-10-23T21:57:27+00:00"
updated_at: "2026-10-25T12:38:51+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-91483", "first_seen_at": "2026-10-23T21:57:27+00:00"}, {"source": "epss", "url": "https://api.first.org/data/v1/epss?cve=CVE-2026-91483", "first_seen_at": "2026-10-25T12:38:51+00:00"}]
---

# Oracle Outside In: local flaw lets a logged-in attacker take over the product

Oracle Outside In Technology, a file-format parsing library shipped in Oracle Fusion Middleware, has a flaw in its Outside In Core component. A local attacker with logon to the host running it can take over the product, and a person must open or process a crafted file for the attack to succeed.

_Summary, check and fix written by a model from the sources; labelled as such._

## How to check

- Check whether Oracle Outside In Technology is installed on the host, for example by searching for its libraries under the Oracle Fusion Middleware home directory.
- Confirm the installed version: `unknown` if the sources do not give the exact check command; the affected supported version is `8.5.8`.

## Fix

- Apply the Oracle Critical Patch Update fix for Oracle Outside In Technology; the fixed version is unknown from the sources.
- Until patched, restrict local logon to the hosts that run Outside In and limit which files they process.

## Timeline

- 2026-10-23T21:57:27+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-91483
- 2026-10-25T12:38:51+00:00 epss https://api.first.org/data/v1/epss?cve=CVE-2026-91483

## From the sources

Vulnerability in the Oracle Outside In Technology product of Oracle Fusion Middleware (component: Outside In Core).   The supported version that is affected is 8.5.8. Easily exploitable vulnerability allows unauthenticated attacker with logon to the infrastructure where Oracle Outside In Technology executes to compromise Oracle Outside In Technology.  Successful attacks require human interaction from a person other than the attacker. Successful attacks of this vulnerability can result in takeover of Oracle Outside In Technology. CVSS 3.1 Base Score 7.8 (Confidentiality, Integrity and Availability impacts).  CVSS Vector: (CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H).

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_Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai_