github-starred/better-auth
2
0
Fork 0
mirror of https://github.com/better-auth/better-auth.git synced 2026-10-18 11:32:15 -05:00
Code Issues 2.5k Packages Projects Releases 112 Wiki Activity

[GH-ISSUE #8898] ReDoS in proxy host header validation regex (utils/url.ts) #28549

New Issue
Open
opened 2026-04-17 20:00:04 -05:00 by GiteaMirror · 0 comments
GiteaMirror commented 2026-04-17 20:00:04 -05:00
Owner
Copy Link
Copy Source

Originally created by @alavesa on GitHub (Apr 1, 2026).
Original GitHub issue: https://github.com/better-auth/better-auth/issues/8898

The hostnameRegex in validateProxyHeader uses nested quantifiers: ([a-zA-Z0-9-]{0,61}[a-zA-Z0-9])? repeated via the outer group. This can trigger catastrophic backtracking on crafted x-forwarded-host header values (e.g., a long string ending in -).

Impact: An attacker sending malicious x-forwarded-host headers could cause CPU exhaustion.

Found by PatchPilots security audit.

Originally created by @alavesa on GitHub (Apr 1, 2026). Original GitHub issue: https://github.com/better-auth/better-auth/issues/8898 The `hostnameRegex` in `validateProxyHeader` uses nested quantifiers: `([a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?` repeated via the outer group. This can trigger catastrophic backtracking on crafted `x-forwarded-host` header values (e.g., a long string ending in `-`). **Impact:** An attacker sending malicious `x-forwarded-host` headers could cause CPU exhaustion. Found by [PatchPilots](https://github.com/alavesa/patchpilots) security audit.
GiteaMirror added the securitybug labels 2026-04-17 20:00:04 -05:00
Sign in to join this conversation.
No Branch/Tag Specified
Branches Tags
Labels
Clear labels
adapter
astro
awaiting external contributor
blocked
breaking
breaking change
bug
c-devops
core
credentials
database
dependencies
devops
devtools
docs
documentation
duplicate
elysia
enhancement
enterprise
expo
express
fastify
good first issue
help wanted
hono
identity
infra
integration
invalid
javascript
locked
maintenance
need-more-information
needs: info
needs: repro
nextjs
nuxt
oauth
organization
P0
payments
perf
platform
plugin
pull-request
Mirrored from GitHub Pull Request
 question
ready
regression
remix
security
social-provider
solid
stale
svelte
tanstack-start
tracking
version-bump
vue
wontfix
No labels bug security
Milestone
No items
No Milestone
Projects
Clear projects
No projects
Assignees
Clear assignees
GiteaMirror ninjasurge (Kaehlen Rog)
No Assignees
1 Participants
Notifications
Due Date
No due date set.
Dependencies

No dependencies set.

Reference: github-starred/better-auth#28549