CVE-2026-91819: MISP: HTTP Method Override Bypasses CSRF and Form Validation in BetterSecurityComponent
Noroxi assessment
Priority: Monitor (action score 27/100)
- The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
- Probability of exploitation in the next 30 days: 0.19% (FIRST EPSS).
- Anyone who can reach it over the internet can trigger it. A low-privileged account is enough. No special conditions are required; it is repeatable.
- Fixed version: MISP MISP 2.5.46.
Low priority for now. Upgrade to MISP MISP 2.5.46 or later.
Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it
Primary sources: NVD · CVE.org · FIRST EPSS
Affected versions of MISP rely on CakePHP request-method override processing in a way that can disable CSRF and form-security validation. CakePHP honors a _method field or X-HTTP-Method-Override header by rewriting the effective request method. For override values outside the normal write verbs POST, PUT, PATCH, and DELETE, CakePHP also clears the parsed request body. MISP’s security component then determines whether to perform _validatePost() and _validateCsrf() based on whether request data remains. With a value such as: _method=GET the body becomes empty before those checks run, so both protections are skipped. A cross-site form containing only that override can therefore reach actions whose parameters are taken from the URL rather than the request body Version affected: ≤2.5.45
- Published
- Sep 15, 2026
- Updated
- Sep 16, 2026
- EPSS
- 0.1% · 9th percentile
- CWE
- CWE-20
Report tools
Action score
27
Monitor
Low priority for now.
- CVSS
- 27 / 40 · 6.9 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 0 / 30 · 0.1%
CISA SSVC decision
- Exploitation
- none
- Automatable
- no
- Technical impact
- partial
Vulnrichment: CISA's decision-tree inputs.
CNA vs NVD score
- NVD
- —
- CNA · CIRCL
- 6.9
- NVD has not scored this yet; the score shown is the CNA’s.
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N
The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.
Get told when this record changes
- Not in KEV: no record of exploitation in the wild
- No public exploit code on record
- A fix has been released
If any of these changes, we'll tell you in the daily email digest.
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Noroxi analysis
What does it mean in your environment?
The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.
We use this product, ask for helpAffected systems
Is your version affected?
Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.
—
Versions reported by the vendor
Affected version ranges reported by the assigning authority (CIRCL). Independent of NVD's CPE analysis and usually ahead of it.
MISP MISP
- before 2.5.46affected · semver
Same product
misp: all recordsOther highest-scoring records for the same primary product.
- CVE-2026-103655MISP TOTP Code Replay Allows Duplicate Authentication Within Validity Period37Monitor
- CVE-2026-90961MISP LdapAuth and LinOTPAuth Authentication Bypass via Empty or Non-String Credentials37Monitor
- CVE-2026-56422MISP Core: Mass Assignment and Object Re-ownership via Unvalidated Request Fields37Monitor
Published before and after this one in the same product
- ← EarlierCVE-2026-90955Sep 14, 2026 · MISP CLI Shell Audit Logs Lose User Identity and CLI Marker After First Lazy Model Load18Monitor
- ← EarlierCVE-2026-90957Sep 14, 2026 · MISP: Stored XSS via Inline-Served SVG Organisation Logos and Report Pictures20Monitor
- Later →CVE-2026-91825Sep 15, 2026 · MISP: Missing Authorization Check for Event Sharing Group When Distribution Field Is Omitted During Edit28Monitor
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
| Product / package | Fixed version | Source |
|---|---|---|
| MISP MISP | 2.5.46 | Vendor (CNA) |
Exploit status
No known public exploit
No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.
Research context
For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.
Timeline
From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.
No dated events beyond publication.
FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).
Patch and commit links
Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.
Credits
All researchersFinders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.
- iglocskaremediation developer
- Claude Opus 5 (1M context)remediation developer
Variant candidates
Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.
- CVE-2026-909611 days apartMISP LdapAuth and LinOTPAuth Authentication Bypass via Empty or Non-String Credentials37Monitor
- CVE-2026-932952 days apartMISP Background Job Argument Injection via Console Path Switches Enables Remote Code Execution34Monitor
- CVE-2026-943836 days apartMISP Blocklist Workflow Module: Arbitrary Script Execution via Unrestricted File Extension34Monitor
- CVE-2026-10323715 days apartMISP: Nested Model Alias Key Bypasses Sanitization to Modify Cross-Tenant Rows33Monitor
- CVE-2026-10332115 days apartMISP Stored Cross-Site Scripting (XSS) via Unvalidated Event Graph Preview Image33Monitor
- CVE-2026-943796 days apartMISP: HTTP Method Bypass of Login Security Controls (Bruteforce Protection and Email OTP)27Monitor
Chain candidates
An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.
—
Bug bounty scope
No known public program.
Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).
Technical details
Attack conditions
- Anyone who can reach it over the internet can trigger it.
- A low-privileged account is enough.
- No special conditions are required; it is repeatable.
If successful
- Confidentiality
- Integrity
- Availability
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- Low
- User interaction
- P
- Scope
- X
Weakness class (CWE)
CWE-20 · Improper Input ValidationCVSS vector
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:N/VI:H/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:X
nvd-secondary
Attack context
MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.
Attack patterns (CAPEC)
- Buffer Overflow via Environment VariablesCAPEC-10likelihood: High · High
- Server Side Include (SSI) InjectionCAPEC-101likelihood: High · High
- Cross Zone ScriptingCAPEC-104likelihood: Medium · High
- Command Line Execution through SQL InjectionCAPEC-108likelihood: Low · Very High
- Object Relational Mapping InjectionCAPEC-109likelihood: Low · High
- SQL Injection through SOAP Parameter TamperingCAPEC-110likelihood: High · Very High
- Double EncodingCAPEC-120likelihood: Low · Medium
- Subverting Environment Variable ValuesCAPEC-13likelihood: High · Very High
ATT&CK techniques
- Obfuscated Files or InformationT1027
- Masquerading: Invalid Code SignatureT1036.001
- Steal Web Session CookieT1539
- Subvert Trust Controls: Code SigningT1553.002
- Impair Defenses:Impair Command History LoggingT1562.003
- Hijack Execution Flow:Dynamic Linker HijackingT1574.006
- Hijack Execution Flow:Path Interception by PATH Environment VariableT1574.007
Change log
- Fix✗ → ✓
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References
Vendor advisories and official records. Exploit/PoC links are deliberately left out.