Security readout for executives and security teams
Plain-English summary
SPIP sites before 4.4.9 have a critical deserialization flaw in public-facing functionality. Exploitation requires an attacker to place malicious serialized content first, likely through prior access or another weakness. If triggered, impact may include code execution. The vendor states SPIP’s security screen does not mitigate this issue.
Executive priority
Treat as urgent for public SPIP sites, especially where content submission or integrations exist. Prioritize upgrading to 4.4.9 because the potential impact includes code execution and the security screen is not protective.
Technical view
The issue is insecure deserialization through the table_valeur filter and DATA iterator, which accept serialized data in the public area. Malicious serialized content can cause arbitrary object instantiation and potentially code execution. Serialized-data support in these components is deprecated and planned for removal in SPIP 5.
Likely exposure
Internet-facing SPIP installations below 4.4.9 are the primary concern. Exposure is higher where users, editors, integrations, or other vulnerabilities can introduce serialized content into reachable public-area processing paths.
Exploitation context
The CVSS score is 9.2, but attack conditions matter: sources state a precondition is needed to place malicious serialized content. No KEV listing or provided source confirms active exploitation.
Researcher notes
The source bundle identifies SPIP before 4.4.9, but the structured affected entry lists 4.4.0 with default unaffected, which is inconsistent. Analysis relies on the title, description, vendor advisory reference, and VulnCheck advisory naming SPIP < 4.4.9.
Mitigation direction
- Upgrade affected SPIP installations to 4.4.9 or later.
- Do not rely on the SPIP security screen for this vulnerability.
- Review vendor guidance for any additional configuration or migration advice.
- Plan removal of serialized-data usage before SPIP 5 compatibility changes.
Validation and detection
- Inventory all SPIP deployments and exposed public sites.
- Confirm the running SPIP version is 4.4.9 or later.
- Review use of table_valeur and DATA iterator with serialized content.
- Check whether untrusted users or integrations can introduce serialized content.
- Monitor vendor and CVE sources for updated affected-version details.
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.
Execution behavior lookup
The CVE wording references code or command execution, so execution technique review may help defensive triage. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2026-27475 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
- Critical
- CVSS
- 9.2 (4.0)
- Known Exploited
- No
- Published
Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
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:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N——Primary CVE scoreVulnerability scoring details
Base CVSS 4.0 score
9.2CriticalVector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
Source materials
- CVE List V5 sourceCVE List V5
- https://blog.spip.net/Mise-a-jour-de-securite-sortie-de-SPIP-4-4-9.htmlCVE reference · vendor-advisory, patch
- https://git.spip.net/spip/spipCVE reference · product
- VulnCheck Advisory: SPIP < 4.4.9 Insecure DeserializationCVE reference · third-party-advisory
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.