CVE-2026-0895: Cpsit/typo3 mailqueue Mailqueue TYPO3 Extension Affected By Vulnerability

MODERATE
Advisory Identifier: GHSA-ggff-9mj3-7246
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CWE-502
Published
Advisory Summary

CVE-2026-0895 is a MODERATE mailqueue typo3 extension affected by vulnerability (CWE-502: Deserialization of Untrusted Data) affecting Cpsit/typo3 mailqueue libraries in the Packagist ecosystem. The issue involves mailqueue typo3 extension affected by insecure deserialization in queueablefiletransport. Remediation is available by upgrading affected packages to version 0.4.3, 0.5.1.

CVE-2026-0895 at a Glance

CVE Identifier CVE-2026-0895
GHSA Identifier GHSA-ggff-9mj3-7246
Severity MODERATE
CVSS v3.1 Base Score N/A
CWE Classification CWE-502: Deserialization of Untrusted Data
Affected Product Cpsit/typo3 mailqueue
Package Ecosystem Packagist
Published Date
Last Updated

How to Fix CVE-2026-0895

To remediate this vulnerability, upgrade all affected Cpsit/typo3 mailqueue dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

cpsit/typo3-mailqueue fixed: 0.4.3 
Upgrade cpsit/typo3-mailqueue to 0.4.3
cpsit/typo3-mailqueue fixed: 0.5.1 
Upgrade cpsit/typo3-mailqueue to 0.5.1
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

inspect dependencies for cpsit/typo3-mailqueue

How to Check if You Are Affected

To determine whether your application is affected by CVE-2026-0895, inspect your project dependencies for Cpsit/typo3 mailqueue:

inspect dependencies for cpsit/typo3-mailqueue

Analyze the terminal output to locate any version of Cpsit/typo3 mailqueue in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 0.4.3), your application is affected.

Note: Verify declared build manifests and deployed runtime container environments.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-502: Deserialization of Untrusted Data, where the product deserializes untrusted data without sufficiently ensuring that the resulting data will be valid. In Cpsit/typo3 mailqueue, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

## Description The extension extends TYPO3’s FileSpool component, which was vulnerable to Insecure Deserialization prior to [TYPO3-CORE-SA-2026-004](https://typo3.org/security/advisory/typo3-core-sa-2026-004). Since the related fix is overwritten by the extension, using the extension with a patched TYPO3 core version still allows for Insecure Deserialization, because the affected vulnerable code was extracted from TYPO3 core to the extension. More information about this vulnerability can be found in the related TYPO3 Core Security Advisory [TYPO3-CORE-SA-2026-004](https://typo3.org/security/advisory/typo3-core-sa-2026-004). ## References * [TYPO3-EXT-SA-2026-001](https://typo3.org/security/advisory/typo3-ext-sa-2026-001) * https://github.com/CPS-IT/mailqueue/commit/fd09aa4e1a751551bae4b228bee814e22f2048db * https://github.com/CPS-IT/mailqueue/commit/12a0a35027bb5609917790a94e43bbf117abf733

CVE-2026-0895 Affected Cpsit/typo3 mailqueue Versions

2 component(s)
Fixed Versions:
0.4.30.5.1
Product / Package Ecosystem Affected Versions Fixed Version
cpsit/typo3-mailqueue
 Packagist
< 0.4.3
0.4.3
cpsit/typo3-mailqueue
 Packagist
≥ 0.5.0
< 0.5.1
0.5.1

References

GitHub Advisory / Wiki ADVISORY
https://github.com/CPS-IT/mailqueue/security/advisories/GHSA-ggff-9mj3-7246
NVD — CVE-2026-0895 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-0895
Security Fix Commit FIX COMMIT
https://github.com/CPS-IT/mailqueue/commit/12a0a35027bb5609917790a94e43bbf117abf733
Security Fix Commit FIX COMMIT
https://github.com/CPS-IT/mailqueue/commit/fd09aa4e1a751551bae4b228bee814e22f2048db
Cpsit/typo3 mailqueue Source Repository REPOSITORY
https://github.com/CPS-IT/mailqueue
Cpsit/typo3 mailqueue Security Information SECURITY
https://typo3.org/security/advisory/typo3-ext-sa-2026-001

Frequently Asked Questions

What is CVE-2026-0895?
CVE-2026-0895 is a security vulnerability in Cpsit/typo3 mailqueue involving mailqueue TYPO3 extension affected by Insecure Deserialization in QueueableFileTransport under CWE-502: Deserialization of Untrusted Data.
Which Cpsit/typo3 mailqueue versions are affected?
Affected versions include releases prior to 0.4.3, 0.5.1 across affected packages: cpsit/typo3-mailqueue.
What version fixes CVE-2026-0895?
Upgrading to 0.4.3, 0.5.1 (or the latest patched release for your respective branch) resolves the vulnerability.
Is cpsit/typo3-mailqueue affected?
Yes, cpsit/typo3-mailqueue is affected in releases prior to 0.4.3, 0.5.1. Upgrade your dependency to 0.4.3, 0.5.1 or later.
What CWE is associated with CVE-2026-0895?
CVE-2026-0895 is classified under CWE-502: Deserialization of Untrusted Data (The product deserializes untrusted data without sufficiently ensuring that the resulting data will be valid.).
How can I check Packagist dependencies for CVE-2026-0895?
Run the dependency tree command: 'inspect dependencies for cpsit/typo3-mailqueue'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-ggff-9mj3-7246",
  "modified" : "2026-01-22T15:52:09Z",
  "published" : "2026-01-21T15:47:44Z",
  "aliases" : [ "CVE-2026-0895" ],
  "summary" : "mailqueue TYPO3 extension affected by Insecure Deserialization in QueueableFileTransport",
  "details" : "## Description\n\nThe extension extends TYPO3’s FileSpool component, which was vulnerable to Insecure Deserialization prior to [TYPO3-CORE-SA-2026-004](https://typo3.org/security/advisory/typo3-core-sa-2026-004). Since the related fix is overwritten by the extension, using the extension with a patched TYPO3 core version still allows for Insecure Deserialization, because the affected vulnerable code was extracted from TYPO3 core to the extension.\n\nMore information about this vulnerability can be found in the related TYPO3 Core Security Advisory [TYPO3-CORE-SA-2026-004](https://typo3.org/security/advisory/typo3-core-sa-2026-004).\n\n## References\n\n* [TYPO3-EXT-SA-2026-001](https://typo3.org/security/advisory/typo3-ext-sa-2026-001)\n* https://github.com/CPS-IT/mailqueue/commit/fd09aa4e1a751551bae4b228bee814e22f2048db\n* https://github.com/CPS-IT/mailqueue/commit/12a0a35027bb5609917790a94e43bbf117abf733",
  "severity" : [ {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:N/VI:L/VA:N/SC:H/SI:H/SA:H"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Packagist",
      "name" : "cpsit/typo3-mailqueue"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "0.4.3"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "Packagist",
      "name" : "cpsit/typo3-mailqueue"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0.5.0"
      }, {
        "fixed" : "0.5.1"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/CPS-IT/mailqueue/security/advisories/GHSA-ggff-9mj3-7246"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-0895"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/CPS-IT/mailqueue/commit/12a0a35027bb5609917790a94e43bbf117abf733"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/CPS-IT/mailqueue/commit/fd09aa4e1a751551bae4b228bee814e22f2048db"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/CPS-IT/mailqueue"
  }, {
    "type" : "WEB",
    "url" : "https://typo3.org/security/advisory/typo3-ext-sa-2026-001"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-502" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-01-21T15:47:44Z",
    "nvd_published_at" : "2026-01-20T08:16:01Z"
  }
}