OmniAuth: Host Header Injection Vulnerability
Written by anthropic/claude-haiku-5.5 from the sources below. Verify against them.
- Exploited
- No known exploitation
- Fix
- Fixed in 2.2.0
- Who is exposed
- Not reported
Do first: Upgrade to a fixed version: 2.2.0.
- Exploitation?/40Exploitation: unknown (data gap). No CISA SSVC exploitation rating yet
- Exposure17/25No login or user action needed per the CVSS vector, reachable over the network without a login · Data gap: No advisory context yet
- Reach?/20Reach: unknown (data gap). No tracked technology or package matched
- Severity6.9/10CVSS 6.9
- No patch0/5No signal
What would change the score
- Would score about 69 if added to CISA KEV
- Would score about 64 if CISA's SSVC rates exploitation active
- Would score about 29 if advisories confirm default setups are exposed
CVE-2026-63183 is not in CISA's Known Exploited Vulnerabilities (KEV) catalog. No public exploit code is tracked. It is rated CVSS 6.9 (medium) and affects omniauth; fixed in 2.2.0.
- Last modified
- Where the record stands: published, rejected by its publisher, or superseded by another id.What do these mean? →
- Published
- Whether CISA lists it in its Known Exploited Vulnerabilities catalog: proof that attackers are using it.What do these mean? →
- Not listed in CISA KEV
- A 0-100 score for how much a CVE matters across the industry: exploitation, exposure, how widely the software is used, severity and whether a fix exists.What do these mean? →
- 24/100 · provisional
- Fix
- Fixed in 2.2.0
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
Summary
OmniAuth, an authentication system for Ruby applications, is affected by a host header injection flaw in applications whose web framework does not validate incoming host headers. A remote attacker who needs no login can send a forged Host header to make the application build provider callback URLs from attacker-chosen host information.
Read the original description
OmniAuth is a flexible authentication system utilizing Rack middleware. Prior to 2.2.0, OmniAuth derives provider callback URLs from request-controlled host information when neither a fixed full_host nor framework-level incoming host validation is configured. A remote unauthenticated client can supply a forged Host header, creating a host header injection risk in applications whose web framework does not verify incoming host headers. Applications using appropriately configured Rails host authorization or a fixed full_host are not affected by this path. This issue is fixed in version 2.2.0.
What to do
Upgrade to a fixed version: 2.2.0.
Timeline
- CVE published
- First seen by cve.now
Affected versions
- omniauth omniauth
fixed in 2.2.0
Evidence 2
- Advisory
- Repository
Corrections
None so far.
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Questions about CVE-2026-63183
Is CVE-2026-63183 being exploited?
It is not in CISA's Known Exploited Vulnerabilities catalog, and CISA's SSVC assessment does not mark exploitation as active. That does not mean it has not been attacked: vendors and researchers can report attacks before CISA lists them. No public exploit code is tracked.Source: cve.now feed data
Which versions are affected by CVE-2026-63183?
omniauth: before 2.2.0.Source: cve.now feed data
How do I fix CVE-2026-63183?
Upgrade to a fixed version: 2.2.0.Source: cve.now feed data