CSRF Vulnerability in rails-ujs

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

6.5 · CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N

EPSS

• CVE-2020-8167: 1.49% estimated exploitation activity in the next 30 days; percentile 74.05 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

There is a vulnerability in rails-ujs that allows attackers to send CSRF tokens to wrong domains. Versions Affected: rails <= 6.0.3 Not affected: Applications which don't use rails-ujs. Fixed Versions: rails = 5.2.4.3, rails = 6.0.3.1 Impact ------ This is a regression of CVE-2015-1840. In the scenario where an attacker might be able to control the href attribute of an anchor tag or the action attribute of a form tag that will trigger a POST action, the attacker can set the href or action to a cross-origin URL, and the CSRF token will be sent. Workarounds ----------- To work around this problem, change code that allows users to control the href attribute of an anchor tag or the action attribute of a form tag to filter the user parameters. For example, code like this: linkto params to code like this: linkto filteredparams def filteredparams

Filter just the parameters that you trust end

Published by the source

7 Jul 2020, 16:34 UTC

Last modified by the source

17 Aug 2023, 05:01 UTC

Source last checked

26 Oct 2026, 15:47 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-xq5j-gw7f-jgj8

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# Patch Next advisory brief: CVE-2020-8167

Advisory: CSRF Vulnerability in rails-ujs
IDs: CVE-2020-8167, GHSA-xq5j-gw7f-jgj8
Record: https://patchnext.com/advisories/cve-2020-8167 (revision 1, source checked 26 Oct 2026, 15:47 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 6.5)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: actionview 6.0.3.1, 5.2.4.3. A vendor fix does not mean a deployment is fixed.

## Affected components
- RubyGems actionview: affected >= 5.0.0, <= 5.2.4.2; >= 6.0.0, <= 6.0.3; fixed in 6.0.3.1, 5.2.4.3

## Suggested inspection (read-only)
- RubyGems actionview: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on actionview.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-xq5j-gw7f-jgj8 (GitHub-reviewed advisory GHSA-xq5j-gw7f-jgj8 lists affected ranges: RubyGems actionview >=5.0.0 =6.0.0 <=6.0.3)

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