Raw 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/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:XSummary
CVE-2026-27475 is a critical-severity Deserialization of Untrusted Data (CWE-502) vulnerability in Spip Spip. Its CVSS base score is 9.2 (Critical).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked in the top 47% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.
The strongest mitigations our analysis identified map to SA-11 (Developer Testing and Evaluation) and SI-10 (Information Input Validation) — see the control section below for these in your framework.
Deeper analysis AI-assisted summary
Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.
CVE-2026-27475 is an insecure deserialization vulnerability (CWE-502) affecting SPIP versions prior to 4.4.9. It occurs in the public area of the software through the table_valeur filter and the DATA iterator, both of which accept serialized data. This flaw allows arbitrary object instantiation when malicious serialized content is processed, potentially leading to code execution. The vulnerability carries a CVSS v3.1 base score of 8.1 (AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H).
An unauthenticated attacker (PR:N) can exploit this remotely (AV:N) without user interaction (UI:N), though it requires high attack complexity (AC:H) due to the precondition of placing malicious serialized content on the target, which necessitates prior access or exploitation of another vulnerability. Successful deserialization triggers arbitrary object instantiation, enabling potential remote code execution with high impacts on confidentiality, integrity, and availability.
Advisories recommend updating to SPIP 4.4.9, which addresses the issue by deprecating the use of serialized data in these components; this functionality will be fully removed in SPIP 5. The SPIP security screen does not mitigate this vulnerability. Relevant resources include the official SPIP security update announcement, the SPIP Git repository, and the VulnCheck advisory.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-8322
Vulnerability Data
SPIP before 4.4.9 allows Insecure Deserialization in the public area through the table_valeur filter and the DATA iterator, which accept serialized data. An attacker who can place malicious serialized content (a pre-condition requiring prior access or another vulnerability) can trigger…
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arbitrary object instantiation and potentially achieve code execution. The use of serialized data in these components has been deprecated and will be removed in SPIP 5. This vulnerability is not mitigated by the SPIP security screen.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Mitigating Controls (NIST 800-53 r5) AI
Developer testing and evaluation can uncover deserialization flaws before deployment.
Input validation directly stops deserialization of untrusted data by ensuring inputs are valid before processing.
Engineering principles such as safe deserialization and input sanitization structurally prevent the weakness from being introduced.
Integrity verification tools can detect malformed or tampered serialized data after the fact.
Mitigating Controls (NIST CSF 2.0) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.
PR.PS-02 addresses only post-deployment updates/patching and cannot prevent introduction of unsafe deserialization code, yet it can remediate some instances when the flaw exists in outdated libraries or components.
Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.
Security testing includes validation of deserialization routines and the use of untrusted data, reducing the likelihood that unsafe object reconstruction will be deployed.
Requiring vetted libraries, regular updates and SAST before release reduces the likelihood that deserialization logic will accept and act on attacker-controlled serialized objects.
Regular scanning of third-party libraries and timely patching reduce the likelihood that unsafe deserialization vulnerabilities remain active.
Mandatory malware scanning of data received over networks or storage media intercepts malicious serialized payloads before they are deserialized by the target application.