CVE-2026-9136
Unauthorized ShadowAttribute modification in MISP via client-supplied identifier
Description
A vulnerability was identified in the ShadowAttribute proposal creation workflow. The add action accepted user-controlled ShadowAttribute request data without removing the id field before saving the record. Because the underlying framework treats a supplied primary key as an instruction to update an existing record, an authenticated user able to submit shadow attribute proposals could provide the identifier of an existing ShadowAttribute and cause that record to be updated instead of creating a new proposal. This can result in unauthorized modification of existing shadow attributes, potentially affecting proposals associated with events the user should not be able to alter. Depending on deployment configuration and accessible API responses, the issue may also expose or move proposal data across event contexts. The vulnerability is caused by trusting a client-supplied primary key during object creation. The fix removes the id field from incoming ShadowAttribute data before processing, ensuring that the endpoint always creates a new proposal rather than updating an existing one. This has been fixed in MISP 2.5.38.
INFO
Published Date :
May 20, 2026, 8:16 p.m.
Last Modified :
June 2, 2026, 4:34 p.m.
Remotely Exploit :
Yes !
Source :
5a6e4751-2f3f-4070-9419-94fb35b644e8
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | MEDIUM | [email protected] | ||||
| CVSS 4.0 | HIGH | 5a6e4751-2f3f-4070-9419-94fb35b644e8 | ||||
| CVSS 4.0 | HIGH | 5a6e4751-2f3f-4070-9419-94fb35b644e8 |
Solution
- Update MISP to version 2.5.38.
- Ensure user inputs do not contain primary keys.
- Validate all user-supplied data.
- Review access controls for proposal creation.
Public PoC/Exploit Available at Github
CVE-2026-9136 has a 1 public
PoC/Exploit available at Github.
Go to the Public Exploits tab to see the list.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-9136.
| URL | Resource |
|---|---|
| https://github.com/MISP/MISP/commit/49911b1d4b6e4517d803e50e3d980aaa4d37c16d | Patch |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-9136 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-9136
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
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The following list is the news that have been mention
CVE-2026-9136 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-9136 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
Initial Analysis by [email protected]
Jun. 02, 2026
Action Type Old Value New Value Added CVSS V3.1 AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N Added CPE Configuration OR *cpe:2.3:a:misp:misp:*:*:*:*:*:*:*:* versions from (including) 2.5.0 up to (excluding) 2.5.38 Added Reference Type CIRCL: https://github.com/MISP/MISP/commit/49911b1d4b6e4517d803e50e3d980aaa4d37c16d Types: Patch -
New CVE Received by 5a6e4751-2f3f-4070-9419-94fb35b644e8
May. 20, 2026
Action Type Old Value New Value Added Description A vulnerability was identified in the ShadowAttribute proposal creation workflow. The add action accepted user-controlled ShadowAttribute request data without removing the id field before saving the record. Because the underlying framework treats a supplied primary key as an instruction to update an existing record, an authenticated user able to submit shadow attribute proposals could provide the identifier of an existing ShadowAttribute and cause that record to be updated instead of creating a new proposal. This can result in unauthorized modification of existing shadow attributes, potentially affecting proposals associated with events the user should not be able to alter. Depending on deployment configuration and accessible API responses, the issue may also expose or move proposal data across event contexts. The vulnerability is caused by trusting a client-supplied primary key during object creation. The fix removes the id field from incoming ShadowAttribute data before processing, ensuring that the endpoint always creates a new proposal rather than updating an existing one. This has been fixed in MISP 2.5.38. Added CVSS V4.0 AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:H/VA:N/SC:N/SI:H/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 Added CWE CWE-639 Added Reference https://github.com/MISP/MISP/commit/49911b1d4b6e4517d803e50e3d980aaa4d37c16d