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CVE-2026-87874NVD status: Awaiting Analysis

Red Hat Ceph Storage 5: Deserialization of Untrusted Data

CVE-2026-87874 is a high-severity deserialization of untrusted data vulnerability in Red Hat Ceph Storage 5 from Red Hat, with a CVSS 3.1 base score of 8.1 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. There is no confirmed exploitation so far. EPSS estimates a 0.72% chance of exploitation within 30 days, higher than 55% of scored CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Check which version of Red Hat Ceph Storage 5 you run against the affected versions below, and install the vendor's latest release.
  2. 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
Red HatRed Hat Ceph Storage 5Not specified in the recordNot stated
Red HatRed Hat Ceph Storage 9Not specified in the recordNot stated
Red HatRed Hat OpenStack Platform 17.1Not specified in the recordNot stated
Red HatRed Hat OpenStack Platform 18.0Not specified in the recordNot 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
HighSuccess depends on conditions outside the attacker's control.
Privileges required
NoneNo account or login is needed.
User interaction
NoneNo action by a victim is required.
Scope
UnchangedImpact stays within the vulnerable component.
Confidentiality
HighAll data handled by the component can be read.
Integrity
HighData or code can be modified at will.
Availability
HighThe component can be taken down completely.

Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H. Scored by CNA (redhat.com).

Official description

A flaw was found in the memcached cache plugin of the community.general Ansible collection. Although its documentation states that records are stored in JSON format, the plugin performs no explicit serialization and relies on python-memcached, which pickles values on write and unpickles them on read. Because memcached is unauthenticated and cache keys are predictable, an attacker able to reach a network-exposed or shared memcached instance can write a crafted pickle payload that is deserialized and executed on the Ansible controller when the poisoned fact cache is next read, leading to remote code execution.

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: no, technical impact: total).

References

Other vulnerabilities in Red Hat Ceph Storage 5

All Red Hat Ceph Storage 5 vulnerabilities

Recent Deserialization of Untrusted Data vulnerabilities

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