---
id: "CVE-2026-85498"
kind: "vulnerability"
aliases: ["CVE-2026-85498"]
title: "polkit: null-byte input causes out-of-bounds read and crash"
severity: "low"
cvss: 3.5
epss: null
exploited: false
status: "open"
category: "infrastructure"
products: []
ecosystems: []
tags: ["infrastructure", "linux", "polkit"]
not_affected_if: ["unknown"]
published_at: "2026-10-29T09:17:08+00:00"
first_seen_at: "2026-10-29T09:23:58+00:00"
updated_at: "2026-10-29T09:24:36+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-85498", "first_seen_at": "2026-10-29T09:23:58+00:00"}]
---

# polkit: null-byte input causes out-of-bounds read and crash

A bug in polkit's authentication agent helper mishandles input that starts with a null byte, causing an integer underflow and an out-of-bounds memory read. An attacker who can supply crafted input can crash the process, causing a denial of service.

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

## Timeline

- 2026-10-29T09:23:58+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-85498

## From the sources

A flaw was found in polkit. When processing input that begins with a null byte, an arithmetic error in the authentication agent helper causes an integer underflow during buffer length calculation, resulting in an out-of-bounds memory read. An attacker capable of supplying crafted input can trigger this flaw, potentially causing an application crash and resulting in a Denial of Service (DoS).

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