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CWE-409Weakness · CWE-409

CVE-2026-61455

MEDIUM · 6.5 CVSS v3.1 Published 2026-07-10
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
71/100
Remediation priority · Elevated
Remotely reachable Zero-click 6 weeks old

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 · unedited
Grav before 2.0.1 contains a decompression bomb vulnerability in ZipArchiver::extract() that lacks limits on uncompressed size, file count, and nesting depth. Attackers can supply a crafted ZIP archive that expands to fill available disk space, causing denial of service by exhausting storage resources.

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 confidence

Grav's ZipArchiver::extract() lacks validation of uncompressed size, file count, and directory nesting depth when processing ZIP archives. Attackers can supply a small crafted ZIP file (a decompression bomb) that expands to consume all available disk space, causing denial of service through storage resource exhaustion.

MitigationImplement size limits, file count limits, and nesting depth checks in ZipArchiver::extract() to reject archives that exceed defined thresholds before decompression begins.

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
Low
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

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

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 checks

Work through these to decide whether this CVE applies to you.

  1. Confirm Grav installation and version
    Check for the presence of Grav by looking for index.php or system/Grav.php in the web root. Retrieve the version from system/defines.php or via bin/grav version command if available.
    Affected if Grav is installed and the ZipArchiver class (system/src/Grav/Common/Archive/ZipArchiver.php) is present without size/file count/nesting validation in its extract() method.
  2. Locate ZipArchiver::extract() method
    Open system/src/Grav/Common/Archive/ZipArchiver.php and locate the extract() method. Inspect the method signature and body for any validation of uncompressed size, file count limits, or directory nesting depth before decompression.
    Affected if The extract() method performs unzip/extraction without validating archive contents against defined thresholds.
  3. Identify ZIP extraction usage points
    Search the codebase for calls to ZipArchiver or ZipArchive extraction (e.g., grep for 'ZipArchiver', 'extractTo', or 'unzip'). Identify if these are triggered by user-uploaded ZIP files or admin operations.
    Affected if The system processes user-supplied or untrusted ZIP archives through ZipArchiver without pre-extraction validation.
  4. Check for existing size or count limits in configuration
    Look for configuration files (config/system.yaml or similar) that may define limits on uncompressed file sizes, maximum file counts, or archive extraction paths. Also check if the PHP memory_limit or post_max_size impose practical constraints.
    Affected if No application-level limits are defined for archive extraction, allowing unbounded decompression.

You are affected if Grav with the vulnerable ZipArchiver::extract() method processes untrusted ZIP archives without pre-extraction validation of size, file count, or nesting depth.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

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 · scoped
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Implement size limits, file count limits, and nesting depth checks in ZipArchiver::extract() to reject archives that exceed defined thresholds before decompression begins.

Recommended fix Moderate confidence

Grav 2.0.1 or later

  1. 1. Identify current Grav installation version by checking the version file or admin panel
  2. 2. Create a complete backup of the Grav installation including all files, database, and configuration
  3. 3. Download Grav 2.0.1 or the latest stable release from the official Grav repository
  4. 4. Replace the existing Grav core files with the new version, preserving custom configuration and content
  5. 5. Verify the ZipArchiver class has been updated with proper limits on uncompressed size, file count, and nesting depth
  6. 6. Test the extraction functionality with both normal and boundary-case ZIP files
  7. 7. Monitor disk usage during ZIP extraction operations to confirm limits are enforced

Generated from the published advisory — verify against the referenced sources before acting.

Have this fixed Scoped from the published advisory
  • Consultation2.0 h
  • Implementation3.0 h
  • Testing2.0 h
  • Review / QA1.0 h
8.0 hours of engineering $1,420
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-61455 in production — separate from our analysis above.

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What this is

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What belongs here
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  • Version or environment caveats, and links to real fixes
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