# CVE-2026-105854: Payload ReDoS in multipart content-type validation

Source: https://junglewise.ai/threats/cve-2026-105854-payload-redos-in-multipart-content-type-validation  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-10-06. Updated: 2026-10-06  
License: CC BY 4.0 with a link back

CVE-2026-105854 · Severity: high · CVSS 4 · Published 2026-10-06

Payload is a headless CMS and backend framework used to build web applications. A malformed multipart request could trigger excessive processing, causing the application to become unresponsive and denying service to legitimate users. An attacker can exploit this remotely by sending a crafted request without authentication.

Technologies: [payload (npm)](https://junglewise.ai/threats/technologies/payload), [Payload CMS Payload](https://junglewise.ai/threats/technologies/payload-cms-payload). Vendors: [npm](https://junglewise.ai/threats/vendors/npm), [Payload CMS](https://junglewise.ai/threats/vendors/payload-cms).

## Quick answers

**Is CVE-2026-105854 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-105854 being exploited in the wild.

**How severe is CVE-2026-105854?** High severity, with a CVSS score of 4, published 6 October 2026.

**Which products and versions are affected?** payload (npm) SEMVER:introduced=3.0.0,fixed=3.90.0; Payload CMS Payload >= 3.0.0, < 3.90.0; >= 4.0.0-canary.0, < 4.0.0-canary.34.

**Is there a fix for CVE-2026-105854?** Yes. payload (npm): upgrade to 3.90.0 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-105854 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-105854?** Check whether you run payload (npm) or Payload CMS Payload at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- payload (npm): upgrade to 3.90.0 or later

  ```sh
  npm install payload@3.90.0
  ```


## Technical details

This is a regular expression denial-of-service (ReDoS) vulnerability in the multipart content-type validation logic, stemming from inefficient regex complexity. The vulnerability affects multipart request parsing and can be triggered remotely over the network without authentication or user interaction, causing unbounded CPU consumption and availability impact.

## Affected products

- Payload CMS Payload >= 3.0.0, < 3.90.0; >= 4.0.0-canary.0, < 4.0.0-canary.34

## Identifiers

- CVE-2026-105854
- GHSA-2g7p-5934-q4w7

## Timeline

- 2026-10-06: disclosed

## References

- [https://api.github.com/users/hwpark6804-gif](https://api.github.com/users/hwpark6804-gif)

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