# CVE-2026-105863: Payload authentication token field handling issue

> Attackers can escalate privileges by mapping custom fields to reserved authentication claims in Payload CMS, requiring a non-default configuration.

- **Severity:** Critical 9.2 (`CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 6 Oct 2026
- **Updated:** 9 Oct 2026
- **Also known as:** GHSA-66wr-7vmr-p5jq

## What is CVE-2026-105863?

CVE-2026-105863 is a critical authentication bypass vulnerability in payloadcms payload, published on 6 Oct 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Payload is a free and open source headless content management system. In versions after 3.0.0 and before 3.90.0, a custom field option that maps a field to a reserved authentication claim name can place unintended values in the authentication token issued at login. This issue is fixed in version 3.90.0.

Weakness: CWE-915 (Improperly Controlled Modification of Dynamically-Determined Object Attributes), CWE-290 (Authentication Bypass by Spoofing)

## Which versions are affected by CVE-2026-105863?

4 open source packages ship an affected version, including payload. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `payload` | npm | From 3.0.0 | 3.90.0 |
| `payload` | npm | From 3.0.0 | 3.90.0 |
| `payload` | npm | From 4.0.0-canary.0 | 4.0.0-canary.34 |
| `payload` | npm | From 4.0.0-canary.0 | 4.0.0-canary.34 |

Products: Payloadcms Payload.

## How do I fix CVE-2026-105863?

Upgrade payload to a fixed version for your release line: 3.90.0 or 4.0.0-canary.34.

## Is CVE-2026-105863 being exploited?

There is no known exploitation of CVE-2026-105863 in the wild and no public exploit code.

## Other vulnerabilities in payloadcms payload

- [CVE-2026-105857](https://insights.sbomify.com/CVE-2026-105857/): Payload: RCE in Payload Form Builder (critical 10.0)
- [CVE-2026-105859](https://insights.sbomify.com/CVE-2026-105859/): Payload: Unauthorized update to collection documents (critical 9.8)
- [CVE-2026-25544](https://insights.sbomify.com/CVE-2026-25544/): Payload has an SQL Injection in JSON/RichText Queries on PostgreSQL/SQLite Adapters (critical 9.8)
- [CVE-2022-27952](https://insights.sbomify.com/CVE-2022-27952/): Unrestricted Upload of File with Dangerous Type in Payload (critical 9.8)
- [CVE-2026-105851](https://insights.sbomify.com/CVE-2026-105851/): Payload: Field access control bypass on auth collections (critical 9.3)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-105863 and fix it if it is affected.

What it is: CVE-2026-105863 is a critical authentication bypass vulnerability in payloadcms payload, published on 6 Oct 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-105863 in the wild and no public exploit code.

Affected packages and fixed versions:
- payload (npm): affected from 3.0.0; fixed in 3.90.0
- payload (npm): affected from 3.0.0; fixed in 3.90.0
- payload (npm): affected from 4.0.0-canary.0; fixed in 4.0.0-canary.34
- payload (npm): affected from 4.0.0-canary.0; fixed in 4.0.0-canary.34

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-2026-105863/ (Markdown: https://insights.sbomify.com/CVE-2026-105863/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-105863
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-105863
- OSV: https://osv.dev/vulnerability/CVE-2026-105863

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-105863/
Summaries are generated and may contain mistakes; the official description above is the record.