CVE-2026-126069: Ruby on Rails cross-site scripting (XSS)

Summary

Action View, the Ruby on Rails framework component that builds HTML view helpers, can be tricked into emitting malformed HTML when an attribute name made only of whitespace is passed to its tag helpers, which can let a crafted attribute value be read by a browser as a separate attribute and possibly enable cross-site scripting. An attacker can reach this remotely without logging in, but it requires a user to take an action and applies only to applications that let users choose custom HTML attribute names.

Written by anthropic/claude-haiku-5.5 from the sources below. Verify against them.

Read the original description

Action View is a framework for handling view template lookup and rendering and provides view helpers for building HTML. Prior to 8.1.4.1 and 8.0.5.2, the fix for CVE-2026-33168 skips blank HTML attribute names in Action View tag helpers, but it tests the name before converting it to a string. A Symbol name made only of whitespace, such as :" ", is not blank, because Symbol#blank? is Symbol#empty?, so it reaches the attribute escaping, which emits an attribute with no name and produces malformed HTML. The asset tag helpers, such as image_tag, video_tag and audio_tag, symbolize their options, so a whitespace String name passed to them takes the same path. A carefully crafted attribute value could then be misinterpreted by the browser as a separate attribute name, possibly leading to XSS. Applications that allow users to specify custom HTML attribute names are affected. This issue is fixed in versions 8.1.4.1 and 8.0.5.2.

cve.now Index

29Pcve.now Index 29 of 100 · methodology v3 · provisional

Exploitation?/40Unknown. No CISA SSVC exploitation rating yet
Exposure7/25Reachable over the network without a login · Unknown: No advisory context yet
Reach17/20Affects Ruby on Rails (a widely deployed server, runtime, framework or database)
Severity4.7/10CVSS 4.7
No patch0/5No signal

What would change the score

Would score about 84 if added to CISA KEV
Would score about 79 if CISA's SSVC rates exploitation active
Would score about 44 if advisories confirm default setups are exposed

How the score works · Rankings

What to do

Upgrade to a fixed version: 8.1.4.1, 8.0.5.2.

Check your systems with an agent

Paste this into a coding or ops agent. It checks your systems read-only and reports a table per asset.

Check whether my systems are affected by CVE-2026-126069 (Action View: Possible XSS vulnerability in Action View tag helpers), using the cve.now data below.

Rules: work read-only. Do not run exploit code, proof-of-concept scripts or scanners that send attack payloads, and do not change any configuration, package, image or deployment. Report findings only.

What cve.now has for CVE-2026-126069 (entry last updated 2026-11-10):
Affected:
- rails rails: from 8.1, fixed in 8.1.4.1; fixed in 8.0.5.2
Fixed versions: 8.1.4.1, 8.0.5.2.
Setup: unknown whether the bug needs a non-default feature or setting. Check the advisory.
CISA KEV: CVE-2026-126069 is not listed as of cve.now's last read.
This KEV status is for CVE-2026-126069 only. If you also check another CVE, look up its own KEV status; never assume it from this one.

How to check:
- Installed software: check what is actually running, not what a repo declares. Read the version from each host, container image and Kubernetes node (the binary's version output, the OS package database, image layers), and check whether the conditions above hold there. Distribution packages may carry a backported fix under an older version number; confirm against the distribution's own advisory.

Verify against the linked advisories before concluding, and cite the date you read each one:
- https://github.com/rails/rails/security/advisories/GHSA-68p9-83h6-5wpj
- https://github.com/rails/rails/commit/9190210606ffe52f92fdc75637f8ff69404f22c8
- https://github.com/rails/rails/commit/f47452533e1f28d847c63181b9d5f8b7243ef9a4
- https://github.com/rails/rails/releases/tag/v8.0.5.2
- https://github.com/rails/rails/releases/tag/v8.1.4.1
Do not conclude an asset is unaffected unless you checked it and the evidence covers both its version and the conditions above. If you could not check something, mark it unknown and say what is missing.

Entry: https://cve.now/CVE-2026-126069
For follow-up questions, use the cve.now MCP server at https://mcp.cve.now/mcp (no authentication), for example get_vulnerability with id CVE-2026-126069.

Timeline

Nov 10, 2026, 8:36 PM UTCCVE published
Nov 10, 2026, 9:26 PM UTCFirst seen by cve.now

Affected versions

rails rails
From 8.1 · fixed in 8.1.4.1; fixed in 8.0.5.2

Evidence 7

Vendor advisory · 1

Establishes: Affected and fixed versions.

Advisory
GitHub · rails/rails · Advisory GHSA-68p9-83h6-5wpj

CVE record · 2

Establishes: The identifier and description.

Record
CVE List · CVE-2026-126069
Record
NVD · CVE-2026-126069

Corrections

None so far.

Something wrong on this page? Report an error. Every fix is listed here.

Questions about CVE-2026-126069

Is CVE-2026-126069 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-2026-126069?

rails: from 8.1 before 8.1.4.1; before 8.0.5.2.Source: cve.now feed data

How do I fix CVE-2026-126069?

Upgrade to a fixed version: 8.1.4.1, 8.0.5.2.Source: cve.now feed data

Action View: Possible XSS vulnerability in Action View tag helpers