⚠ Reference material — not professional advice. Test in staging, back up first, verify against your specific version. Use your own judgment for your environment.
● Not verified

How to Fix CVE-2026-33637: SSRF Vulnerability in faraday

Other vulnerabilities in the same area that are worth patching alongside this one:

*By Sai Kiran Pandrala*

⚡ At a glance
SeverityNot verified - see advisory
Actively exploited?Not currently listed in CISA KEV
Affected>= 2.0.0, <= 2.14.2
Fixed inversion
Type (CWE)CWE-918: Server-Side Request Forgery (SSRF)

What is CVE-2026-33637?

CVE-2026-33637 is an server-side request forgery (SSRF) flaw in faraday. The product makes server-side HTTP requests to attacker-controlled URLs, exposing internal services and cloud metadata endpoints. Vendor description: Faraday is an HTTP client library abstraction layer that provides a common interface over many adapters. Versions 2.0.0 through 2.14.1 still allow protocol-relative host override when the request target is passed as a URI object (rather than a String) to Faraday::Connection#build_exclusive_url.

Why this CVE matters

Server-side request forgery routinely chains into cloud-metadata theft, internal service enumeration, and credential exfiltration. In cloud-hosted deployments the impact is often more severe than on-prem because of the metadata service exposure.

For deployments of faraday that have been exposed to the public internet during the disclosure window, the operating assumption should be that scanning has already happened. Even where exploitation has not been publicly observed, scanning for the vulnerable fingerprint is cheap and routine. Patching closes the door; log review and credential rotation close out the rest of the response.

Am I affected?

You are affected if your installation matches any of these version ranges:

Check your installed version against the list above. If you cannot determine the version, treat the system as affected and follow the upgrade path below.

Open faraday's About dialog or run the vendor-documented version-check command. Compare the result against the affected ranges in the advisory.

How to fix CVE-2026-33637

  1. Read the vendor advisory in full: https://github.com/lostisland/faraday/security/advisories/GHSA-5rv5-xj5j-3484
  2. Upgrade faraday to the patched build listed in the vendor advisory.
  3. Back up the configuration (and database, where applicable) before upgrading.
  4. Apply the patch in a maintenance window. For HA pairs, upgrade the standby node first, fail over, then upgrade the former primary.
  5. Restart the affected service so the patched binary loads, then verify the new version (see verification section).

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Patch via your OS package manager

Vendor advisory (always check this first for exact fixed version and any

prerequisites): https://github.com/lostisland/faraday/security/advisories/GHSA-5rv5-xj5j-3484


# Debian / Ubuntu: pull the patched build of faraday from your distro repository.
sudo apt update
sudo apt install --only-upgrade faraday

# RHEL / Rocky / AlmaLinux / Fedora
sudo dnf upgrade faraday

# openSUSE
sudo zypper update faraday

# Verify the running version matches the fixed-in version (2.14.3).
faraday --version || dpkg -s faraday | grep -i version || rpm -q faraday


# Windows: pull the latest cumulative updates that include this CVE's fix.
Install-Module PSWindowsUpdate -Force -SkipPublisherCheck
Import-Module PSWindowsUpdate
Get-WindowsUpdate -AcceptAll -Install -AutoReboot

# If a specific KB is referenced in the advisory, install it directly.
# Get-WindowsUpdate -KBArticleID KBxxxxxxx -AcceptAll -Install -AutoReboot

Verify the fix landed


# Vendor advisory: https://github.com/lostisland/faraday/security/advisories/GHSA-5rv5-xj5j-3484
# 1. Confirm the running version matches the fixed-in version listed above.

# 2. Re-scan with your vulnerability scanner (Nessus, Qualys, Tenable, OpenVAS).
#    The scanner should no longer flag this CVE on the patched target.

# 3. Inspect recent service / kernel logs for crash-loops or rollback events.
journalctl -u <service> --since "10 minutes ago"
dmesg --since "10 minutes ago"

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If you cannot patch immediately

Block outbound network access from the affected service to internal subnets and cloud metadata endpoints (e.g. 169.254.169.254). Apply the patched build.

How to verify the fix worked

If your installation was internet-reachable during the disclosure window, treat log review as part of the remediation rather than an optional follow-up. Look for unusually long URI paths containing traversal sequences, unexpectedly large responses from the affected endpoint, and outbound requests from the application to internal addresses or cloud-metadata endpoints. Treat any sensitive file the bug could disclose as exposed.

Frequently asked questions

Is CVE-2026-33637 being exploited in the wild?

Public exploitation has not been confirmed by CISA at the time of writing. Treat the patch as time-sensitive anyway; reports often lag actual abuse.

Will a WAF or IDS rule fully mitigate CVE-2026-33637?

No. Network-layer filters can reduce noise and slow opportunistic scanners, but they will not stop a determined attacker. The vendor patch is the only durable fix.

How long should I plan for the upgrade?

Typical vendor-documented upgrade windows for faraday run from a few minutes to under an hour depending on cluster size. Test in a staging environment first and follow the vendor's documented HA upgrade order.

References

*This guide was assembled from the official vendor advisory, the NVD record, and the CISA KEV catalog entry on 2026-05-25. Always confirm against the vendor advisory before applying changes in production.*