# CVE-2026-85498: Polkit: regression in cve-2026-4897 fix (polkit read_cookie()) - stack buffer underflow


- **Severity:** Low 3.5 (`CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L`)
- **Exploited in the wild:** Not known
- **Fix available:** Yes
- **Published:** 29 Oct 2026
- **Updated:** 29 Oct 2026
- **Also known as:** DEBIAN-CVE-2026-85498, GHSA-cvc4-pw4g-cgpc, MGASA-2026-0485, OESA-2026-4000, OESA-2026-4001, OESA-2026-4002, OESA-2026-4003, OESA-2026-4050, UBUNTU-CVE-2026-85498, USN-8762-1, openSUSE-SU-2026:12203-1

## What is CVE-2026-85498?

CVE-2026-85498 is a low-severity vulnerability in Red Hat Enterprise Linux 10, published on 29 Oct 2026. 

### Official description

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).

Weakness: CWE-125 (Out-of-bounds Read)

## Which versions are affected by CVE-2026-85498?


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `polkit` | openSUSE:Tumbleweed | All versions | 128-1.1 |

## How do I fix CVE-2026-85498?

Upgrade to a fixed version.

## Is CVE-2026-85498 being exploited?

There is no known exploitation of CVE-2026-85498 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-85498 and fix it if it is affected.

What it is: CVE-2026-85498 is a low-severity vulnerability in Red Hat Enterprise Linux 10, published on 29 Oct 2026. 
Exploitation: There is no known exploitation of CVE-2026-85498 in the wild and no public exploit code.

Affected product: Red Hat Enterprise Linux 10. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-85498/ (Markdown: https://insights.sbomify.com/CVE-2026-85498/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-85498
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-85498
- OSV: https://osv.dev/vulnerability/CVE-2026-85498

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-85498/
Summaries are generated and may contain mistakes; the official description above is the record.