Grav: Decompression Bomb via ZipArchiver - Missing Extraction Limits

Exploitation

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

CVSS

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

EPSS

• CVE-2026-61455: 0.30% estimated exploitation activity in the next 30 days; percentile 22.87 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.
• CVE-2026-61690: 0.53% estimated exploitation activity in the next 30 days; percentile 44.90 (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.

Summary ZipArchiver::extract() lacks limits on uncompressed size, file count, and nesting depth, creating a distinct, unpatched variant of the GHSA-2vcx-h8p2-9pg9 zip bomb vulnerability. While the parallel method Installer::unZip() received comprehensive limits, ZipArchiver::extract() remains unprotected, leaving a separate code path vulnerable to the same attack vector. The vulnerability is a distinct, unpatched variant of the bug described in GHSA-2vcx-h8p2-9pg9, as it affects a separate code path in the same codebase, implementing the same abstract class. --- Details Vulnerable code - system/src/Grav/Common/Filesystem/ZipArchiver.php:29-58: What's missing vs Installer::unZip(): | Protection | Installer::unZip() | ZipArchiver::extract() | |-----------|---------------------|------------------------| | Zip Slip guard | ✅ | ✅ | | Max uncompressed size | ✅ (1 GiB) | ❌ | | Max file count | ✅ (50000) | ❌ | | Max nesting depth | ✅ (48) | ❌ | | Pre-extraction validation | ✅ All entries…

Published by the source

2 Sep 2026, 21:35 UTC

Last modified by the source

2 Sep 2026, 21:45 UTC

Source last checked

26 Oct 2026, 14:53 UTC

1. Revision 2 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-928x-9mpw-8h56

2. Revision 1 · created · 24 Oct 2026

   Published from osv record GHSA-928x-9mpw-8h56

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# Patch Next advisory brief: CVE-2026-61455

Advisory: Grav: Decompression Bomb via ZipArchiver - Missing Extraction Limits
IDs: CVE-2026-61455, GHSA-928x-9mpw-8h56
Record: https://patchnext.com/advisories/cve-2026-61455 (revision 2, source checked 26 Oct 2026, 14:53 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: getgrav/grav 2.0.1. A vendor fix does not mean a deployment is fixed.

## Affected components
- Packagist getgrav/grav: affected < 2.0.1; fixed in 2.0.1

## Suggested inspection (read-only)
- Packagist getgrav/grav: 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 getgrav/grav.
- 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://osv.dev/vulnerability/GHSA-928x-9mpw-8h56 (OSV record GHSA-928x-9mpw-8h56 lists affected ranges: Packagist getgrav/grav >=0 <2.0.1 (fixed))
- Verified: https://github.com/advisories/GHSA-928x-9mpw-8h56 (GitHub-reviewed advisory GHSA-928x-9mpw-8h56 lists affected ranges: Packagist getgrav/grav >=0 <2.0.1)

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