# CVE-2026-45822: SamVerschueren decode-uri-component denial of service in decode function

Source: https://junglewise.ai/threats/cve-2026-45822-samverschueren-decode-uri-component-denial-of-service-in-decode  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-06-30. Updated: 2026-09-25  
License: CC BY 4.0 with a link back

CVE-2026-45822 · Severity: medium · CVSS 4 · Published 2026-06-30

The decode-uri-component npm library is used to parse and decode URL-encoded strings in web applications. An attacker can supply specially crafted malformed percent-encoded input that causes the decoding function to consume excessive CPU resources, making the application unresponsive. This is an availability attack with no data exposure or code execution risk.

Technologies: [decode-uri-component (npm)](https://junglewise.ai/threats/technologies/npm-decode-uri-component). Vendors: [npm](https://junglewise.ai/threats/vendors/npm).

## Quick answers

**Is CVE-2026-45822 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-45822 being exploited in the wild.

**How severe is CVE-2026-45822?** Medium severity, with a CVSS score of 4, published 30 June 2026.

**Which products and versions are affected?** decode-uri-component (npm) SEMVER:introduced=0,fixed=0.5.0; SamVerschueren Decode-Uri-Component 0.1.0 through 0.4.1.

**Is there a fix for CVE-2026-45822?** Yes. decode-uri-component (npm): upgrade to 0.5.0 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-45822 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-45822?** Check whether you run decode-uri-component (npm) or SamVerschueren Decode-Uri-Component 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

- decode-uri-component (npm): upgrade to 0.5.0 or later

  ```sh
  npm install decode-uri-component@0.5.0
  ```


## Technical details

The vulnerability is an algorithmic complexity issue (CWE-407 / CWE-400) in the decodeUriComponent() function. The root cause is inefficient handling of malformed percent-encoded sequences, which can undergo exponential decoding iterations. An attacker with the ability to supply input directly to the function (or via a dependency processing URL/query/path data) can craft payloads that trigger pathological performance. No authentication is required; the attack is network-reachable for web applications accepting URL input. The exploit results in excessive CPU consumption and application unavailability, but does not cause memory corruption or information disclosure. Patch version 0.5.0 addresses this issue; workaround includes input size limiting.

## Affected products

- Sam Verschueren decode-uri-component <= 0.4.2

## Identifiers

- CVE-2026-45822
- GHSA-vcc3-ghjq-m6fr

## Timeline

- 2026-06-29: disclosed: Published by SamVerschueren to GitHub
- 2026-06-29: patched: Version 0.5.0 released with fix
- 2026-08-31: advisory: GitHub Advisory Database review completed

## References

- [https://api.github.com/users/bnbdr](https://api.github.com/users/bnbdr)
- [https://github.com/bnbdr](https://github.com/bnbdr)
- [https://api.github.com/users/bnbdr/gists%7B/gist_id%7D](https://api.github.com/users/bnbdr/gists%7B/gist_id%7D)
- [https://api.github.com/users/bnbdr/repos](https://api.github.com/users/bnbdr/repos)
- [https://avatars.githubusercontent.com/u/24456233?v=4](https://avatars.githubusercontent.com/u/24456233?v=4)
- [https://api.github.com/users/bnbdr/events%7B/privacy%7D](https://api.github.com/users/bnbdr/events%7B/privacy%7D)

## Related threats

- [decode-uri-component ReDoS in percent-encoding handling](https://junglewise.ai/threats/cve-2026-118664-decode-uri-component-provides-a-more-robust-alternative-to)
- [decode-uri-component denial of service via improper input validation](https://junglewise.ai/threats/cve-2022-38900-decode-uri-component-denial-of-service-via-improper-input)