CyberSecBulletin
CVE-2026-55220NVD status: Deferred

pimcore: Deserialization of Untrusted Data

Published Updated By the CyberSecBulletin desk

CVE-2026-55220 is a critical-severity deserialization of untrusted data vulnerability in pimcore, with a CVSS 4.0 base score of 9.3 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected pimcore versions: < 11.5.19; >= 12.0.0-RC1, < 12.3.10; >= 2026.1.0, < 2026.1.6. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.68% chance of exploitation within 30 days, higher than 53% of scored CVEs.

Patch this week

Critical severity: a successful attack would have severe impact.

What to do

  1. Check which version of pimcore you run against the affected versions below, and install the vendor's latest release.
  2. Read the advisory on github.com for workarounds and exact fixed builds.
  3. Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.

Affected products and versions

VendorProductAffected versionsFixed in
Pimcorepimcore< 11.5.19; >= 12.0.0-RC1, < 12.3.10; >= 2026.1.0, < 2026.1.6Not stated

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
NetworkCan be exploited remotely over a network, including the internet.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Attack requirements
NoneThe attack does not depend on a particular deployment or configuration.
Privileges required
NoneNo account or login is needed.
User interaction
NoneNo action by a victim is required.
Confidentiality (vulnerable system)
HighSerious loss of confidentiality on the vulnerable system.
Integrity (vulnerable system)
HighSerious loss of integrity on the vulnerable system.
Availability (vulnerable system)
HighSerious loss of availability on the vulnerable system.
Confidentiality (other systems)
NoneNo loss of confidentiality on systems beyond the vulnerable one.
Integrity (other systems)
NoneNo loss of integrity on systems beyond the vulnerable one.
Availability (other systems)
NoneNo loss of availability on systems beyond the vulnerable one.

Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X. Scored by CNA (github.com).

Official description

Pimcore is an Open Source Data & Experience Management Platform. Prior to 11.5.19, 12.3.10, and 2026.1.6, Pimcore\Model\DataObject\ClassDefinition\Data\Hotspotimage::getDataFromResource() in models/DataObject/ClassDefinition/Data/Hotspotimage.php passes the field __hotspots object-store column to Pimcore\Tool\Serialize::unserialize() without an allowed-classes restriction after JSON decoding fails. An attacker with a separate capability to write crafted PHP serialized bytes into that column can instantiate available classes and trigger magic methods when an affected DataObject is loaded, which can produce arbitrary file writes or code execution through bundled gadget chains. The related ImageGallery, Block, and Video callers use the same fallback pattern, but the identified June fix changes the Hotspotimage caller only. This issue is fixed for Hotspotimage in versions 11.5.19, 12.3.10, and 2026.1.6.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Deserialization of Untrusted Data

The product deserializes untrusted data without sufficiently ensuring that the resulting data will be valid.

How developers prevent this class of flaw

  • If available, use the signing/sealing features of the programming language to assure that deserialized data has not been tainted. For example, a hash-based message authentication code (HMAC) could be used to ensure that data has not been modified.
  • When deserializing data, populate a new object rather than just deserializing. The result is that the data flows through safe input validation and that the functions are safe.
  • Explicitly define a final object() to prevent deserialization.

More Deserialization of Untrusted Data vulnerabilities (CWE-502)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: yes, technical impact: total).
  3. Record last changed materially (score, affected products, status or references).

References

Other vulnerabilities in pimcore

All pimcore vulnerabilities

Recent Deserialization of Untrusted Data vulnerabilities

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