oak: ReDoS in x-forwarded-proto and x-forwarded-for headers

published 2025-08-09 15 mo ago modified 2026-06-17 4 mo ago also GHSA-r3v7-pc4g-7xp9 , EUVD-2025-24026

cvss: 5.3; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.4%; EPSS 0.4% chance of exploitation in 30 days, percentile 35%
public exploits: 0; none known

oak is a middleware framework for Deno's native HTTP server, Deno Deploy, Node.js 16.5 and later, Cloudflare Workers and Bun. In versions 17.1.5 and below, it's possible to significantly slow down an oak server with specially crafted values of the x-forwarded-proto or x-forwarded-for headers.

Patch / fix

links 1

github.com/oakserver/oak@b60e603 commit

CISA SSVC

Exploitation: Proof of concept is public
Automatable: yes
Technical impact: partial
Assessed: 14 mo ago (2025-08-11)

Exploit prediction

0.41% chance of exploitation in the next 30 days, higher than 35% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
CNA	3.1	5.3	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
GitHub	3.1	5.3	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

Affected packages

ecosystem	package	affected	fixed in
npm	@oakserver/oak	<=14.1.0	no fix listed

Affected products

oakserver oak

Classification

Weakness

CWE-400 Uncontrolled Resource Consumption
CWE-1333 Inefficient Regular Expression Complexity

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary