CVE-2026-61453
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedGrav v2.0.0 contains a cross-site scripting vulnerability (fixed in 2.0.1). The XSS blueprint validator (Security::detectXss()) runs on raw page content before Twig processing. When Twig content processing is enabled (twig_content.process_enabled: true), an attacker with page-write API permission can use Twig's string concatenation operator (~) to dynamically construct event handler names, dangerous tag names, or dangerous protocols at render time (e.g. {% set x = "on" ~ "error" %}). The validator sees only the harmless Twig expression and allows the content, but after Twig rendering the output (rendered via {{ page.content|raw }}) contains an active payload such as <img src=1 onerror=alert(1)>, executing arbitrary JavaScript in visitors' browsers.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · high confidenceGrav CMS v2.0.0 has a post-render XSS vulnerability where the XSS blueprint validator (Security::detectXss()) runs on raw Twig content before processing, not after. When twig_content.process_enabled is true, attackers with page-write API permissions can bypass the validator using Twig's string concatenation operator (~) to construct payloads like {% set x = "on" ~ "error" %} that become active XSS (e.g., <img src=1 onerror=alert(1)>) after rendering via {{ page.content|raw }}.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- Low
- Privileges
- None
- User interaction
- Required
- Scope
- Changed
- Confidentiality
- Low
- Integrity
- Low
- Availability
- None
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Identify Grav CMS versionCheck the version number in system/src/Grav/Common/Grav.php or in your composer.json file under the 'version' or 'grav-core' package entryAffected if The installed version is exactly 2.0.0 (prior to the fix)
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Verify twig_content.process_enabled settingInspect your system.yaml or theme configuration file for the 'twig_content.process_enabled' setting. Typically found in user/config/system.yaml under the twig sectionAffected if twig_content.process_enabled is set to true (enabled)
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Confirm page-write API access existsReview user account permissions and any API access configurations to determine if untrusted or low-privilege users have page-write or content-creation API permissionsAffected if Users with limited privileges can create or modify page content via the API
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Inspect page content for Twig concatenation patternsSearch page markdown or content files (in user/pages/ or via the admin API) for Twig tags containing the ~ operator, such as {% set x = "on" ~ "error" %} or similar string concatenation patterns that could form event handlersAffected if Any page content contains Twig concatenation syntax that could bypass the pre-render XSS validator
You are affected if running Grav CMS v2.0.0 with twig_content.process_enabled enabled AND your system allows page-write access to users who could inject Twig concatenation payloads that become active XSS after rendering.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
dbcve · scopedUpgrade to Grav v2.0.1 or later which includes the fix; alternatively, disable twig_content.process_enabled if not required for the site's functionality.
Grav v2.0.1
- Upgrade Grav from v2.0.0 to v2.0.1 to obtain the security fix
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation1.0 h
- Implementation1.0 h
- Testing2.0 h
- Review / QA1.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $1,376.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-61453 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2026-61453 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
- No weaponised exploit code, or anything meant to cause harm
- No spam, self-promotion, credentials, or personal data