Security readout for executives and security teams
Plain-English summary
CVE-2026-0895 affects the TYPO3 Mailqueue extension. It reintroduced vulnerable FileSpool deserialization code that TYPO3 core had already fixed. A patched TYPO3 core alone may not protect sites using this extension. The CVE is rated medium, but compromise could have serious impact after an attacker gains required local/privileged conditions.
Executive priority
Handle in the next scheduled security patch cycle, or sooner for sensitive TYPO3 environments. The issue is not reported as actively exploited, but patched core systems may remain vulnerable if this extension is present.
Technical view
Mailqueue extends TYPO3 FileSpool and overwrites the core fix from TYPO3-CORE-SA-2026-004, leaving CWE-502 insecure deserialization in the extension. CVSS 4.0 is 5.2 with local attack vector, low privileges, no user interaction, and attack prerequisites. Listed affected package is cpsit/typo3-mailqueue, including versions 0 through 0.5.0.
Likely exposure
Exposure is limited to TYPO3 installations using the Mailqueue extension package cpsit/typo3-mailqueue in the affected version range. Systems only running TYPO3 core without this extension are not indicated as affected by this CVE.
Exploitation context
The source bundle does not report active exploitation, and KEV is false. CVSS indicates exploitation requires local access, low privileges, and prerequisites, but no user interaction. Do not treat this as remotely exploitable without additional vendor evidence.
Researcher notes
Key nuance: the extension extracted and overwrote code previously fixed in TYPO3 core. Assess extension code separately from core patch status. The provided evidence does not include exploit details or a confirmed fixed release number beyond patch references.
Mitigation direction
- Review TYPO3 EXT-SA-2026-001 for the vendor-approved remediation path.
- Update Mailqueue to a fixed release if the advisory names one.
- Apply the referenced upstream patch commits only through normal change control.
- Do not rely on a patched TYPO3 core alone for affected Mailqueue deployments.
Validation and detection
- Inventory TYPO3 sites for the Mailqueue extension package cpsit/typo3-mailqueue.
- Confirm whether installed Mailqueue versions are within the listed affected range.
- Verify remediation against TYPO3 EXT-SA-2026-001 and the referenced patch commits.
- Document systems where TYPO3 core is patched but Mailqueue remains unpatched.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-502: Code execution behavior lookup
Code execution and unsafe deserialization weaknesses often justify reviewing execution behavior and process telemetry. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCVE-2026-0895 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- Medium
- CVSS
- 5.2 (4.0)
- Known Exploited
- No
- Published
Vector: 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
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest 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——Primary CVE scoreVulnerability scoring details
Base CVSS 4.0 score
5.2MediumVector: 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
Source materials
- CVE List V5 sourceCVE List V5
- https://typo3.org/security/advisory/typo3-ext-sa-2026-001CVE reference · vendor-advisory
- https://github.com/CPS-IT/mailqueue/commit/fd09aa4e1a751551bae4b228bee814e22f2048dbCVE reference · patch
- https://github.com/CPS-IT/mailqueue/commit/12a0a35027bb5609917790a94e43bbf117abf733CVE reference · patch
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Deserialization of Untrusted Data
Deserialization of Untrusted Data represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.