Raw vector
CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:L/VI:L/VA:N/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-2026-25101 is a medium-severity Session Fixation (CWE-384) vulnerability in Bludit Bludit. Its CVSS base score is 4.8 (Medium).
Operationally, exploitation aligns with the MITRE ATT&CK technique Steal Web Session Cookie (T1539); ranked at the 29th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.
The strongest mitigations our analysis identified map to SC-23 (Session Authenticity) and AC-12 (Session Termination) — 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-2026-25101 is a session fixation vulnerability in Bludit, an open-source flat-file CMS. The flaw allows an attacker to set a user's session identifier before authentication, and this session ID remains unchanged after the user successfully logs in. This predictable session handling, tied to CWE-384 (Session Fixation), enables session hijacking and was assigned a CVSS v3.1 base score of 9.8 (AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H). The issue affects Bludit versions prior to 3.17.2.
Unauthenticated attackers can exploit this remotely with low complexity and no user interaction required. By forcing a victim to use a predetermined session ID—such as through a crafted link or malicious site—the attacker positions themselves to hijack the victim's authenticated session once login occurs. Successful exploitation grants full access to the victim's privileges, potentially allowing confidentiality breaches, data manipulation, or other administrative actions depending on the victim's role.
Mitigation is available via the official patch in Bludit version 3.17.2, as detailed in the project's GitHub release notes. Security advisories, including those from CERT.pl, recommend immediate upgrades for affected installations to regenerate session IDs properly upon authentication.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-16581
- 🇵🇱 CERT-PL: cert.pl
Vulnerability Data
Bludit allows user's session identifier to be set before authentication. The value of this session ID stays the same after authentication. This behavior enables an attacker to fix a session ID for a victim and later hijack the authenticated session.…
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This issue was fixed in version 3.17.2.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Control response
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V4.4.4V7.6.2
Mitigating Controls (NIST 800-53 r5) AI
Requires protection of session authenticity, which directly stops an attacker from using a stolen or fixed session identifier after authentication.
Limits the lifetime of any session (fixed or not), thereby reducing the window during which a stolen identifier remains usable.
Enforces that only properly authorized (i.e., freshly authenticated) sessions can access resources, making a pre-existing fixed session ID unusable.
Forces re-authentication under defined conditions, which should result in issuance of a fresh session identifier and invalidation of any prior one.
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.
Proper authentication processes must invalidate prior session identifiers to prevent fixation attacks.
Managing identities and credentials includes handling session identifiers as temporary credentials that must be invalidated on re-authentication.
Protecting and verifying identity assertions encompasses secure handling and regeneration of session tokens.
Configuration baselines can enforce session regeneration and timeout settings that block fixation.
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 can detect session-fixation issues, yet the weakness absence does not replace comprehensive testing.
Access-control policy can mandate session invalidation on re-authentication, but does not prescribe the technical mechanism.
Identity-management procedures can require new session tokens after login, yet the control is broader than session handling.
Authentication-information rules can include session-token lifecycle requirements, but the control focuses on credential management.
Secure-SDLC requirement can embed session-fixation checks, but eliminating the weakness does not satisfy the full SDLC control.
Application-security requirements can specify session handling, yet the weakness fix alone does not meet the broader requirement.