CIRCL MISP up to 2.5.47 Discussion Posting access control

Summaryinfo

A vulnerability marked as critical has been reported in CIRCL MISP up to 2.5.47. Affected by this issue is some unknown functionality of the component Discussion Posting. This manipulation causes access control. This vulnerability appears as CVE-2026-103858. The attack may be initiated remotely. There is no available exploit. It is suggested to upgrade the affected component.

Detailsinfo

A vulnerability classified as critical was found in CIRCL MISP up to 2.5.47. Affected by this vulnerability is an unknown code of the component Discussion Posting. The manipulation with an unknown input leads to a access control vulnerability. The CWE definition for the vulnerability is CWE-284. The product does not restrict or incorrectly restricts access to a resource from an unauthorized actor. As an impact it is known to affect confidentiality, integrity, and availability. The summary by CVE is:

MISP contains an incomplete authorization check in the discussion posting functionality. When a user submits a post to a thread or replies to an existing post, the application only verified whether the target thread was restricted to a single organization (org-only distribution). It did not enforce the full thread access control list, including sharing-group membership and event-level visibility. As a result, an authenticated user who is outside the relevant sharing group or who does not have visibility on the associated event could: - Read the thread title and the content of the quoted post - Submit a new post into the discussion thread This constitutes both an information disclosure (reading restricted thread and post content) and an integrity issue (injecting content into a thread the user is not authorized to participate in). Affected: <2.5.48

The advisory is shared at github.com. This vulnerability is known as CVE-2026-103858 since 10/01/2026. The exploitation appears to be easy. The attack can be launched remotely. Neither technical details nor an exploit are publicly available. MITRE ATT&CK project uses the attack technique T1068 for this issue.

Upgrading to version 2.5.48 eliminates this vulnerability. Applying the patch 79fbd4c75 is able to eliminate this problem. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2026-90770). Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Productinfo

Vendor

• CIRCL

Name

• MISP

Version

• 2.5.0
• 2.5.1
• 2.5.2
• 2.5.3
• 2.5.4
• 2.5.5
• 2.5.6
• 2.5.7
• 2.5.8
• 2.5.9
• 2.5.10
• 2.5.11
• 2.5.12
• 2.5.13
• 2.5.14
• 2.5.15
• 2.5.16
• 2.5.17
• 2.5.18
• 2.5.19
• 2.5.20
• 2.5.21
• 2.5.22
• 2.5.23
• 2.5.24
• 2.5.25
• 2.5.26
• 2.5.27
• 2.5.28
• 2.5.29
• 2.5.30
• 2.5.31
• 2.5.32
• 2.5.33
• 2.5.34
• 2.5.35
• 2.5.36
• 2.5.37
• 2.5.38
• 2.5.39
• 2.5.40
• 2.5.41
• 2.5.42
• 2.5.43
• 2.5.44
• 2.5.45
• 2.5.46
• 2.5.47

License

• open-source

CPE 2.3info

• 🔒
• 🔒
• 🔒

CPE 2.2info

• 🔒
• 🔒
• 🔒

CVSSv4info

CVSSv3info

CVSSv2info

Exploitinginfo

Threat Intelligenceinfo

Countermeasuresinfo

Timelineinfo

Sourcesinfo

Entryinfo

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Discussion