CVE-2026-103662NONE
EPSS 0.3%
MISP contains a reflected cross-site scripting (XSS) vulnerability in the legacy taxonomy tag management confirmation forms (add tag and disable tag).
The affected forms echoed a user-supplied tag name value from the request unescaped into the rendered HTML output. An attacker who can induce a site administrator to visit a crafted URL containing a malicious tag name parameter can execute arbitrary JavaScript in the administrator's browser session.
Preconditions:
- The target must be running a MISP instance with the legacy taxonomy tag confirmation views enabled.
- The victim must be an authenticated site administrator.
- The victim must navigate to the attacker-crafted URL (e.g., via a phishing link).
Security impact:
- Execution of arbitrary client-side script in the context of the administrator's browser.
- Potential theft of session tokens, CSRF tokens, or other sensitive data accessible from the page.
- Potential for performing privileged actions on behalf of the administrator within the MISP interface.
Affected versions: <2.5.48.
CVE-2026-103655NONE
EPSS 0.3%
MISP contains a vulnerability in its two-factor authentication (TOTP) verification process that permits a valid one-time code to be accepted more than once within its time-based validity window.
The issue exists in the user login flow where a TOTP code is verified as a second authentication factor. Because the system did not record whether a given TOTP period had already been consumed, the same code remained valid for its entire time window (typically 30 seconds). An attacker who captures a legitimate code during a user's login could replay it to authenticate a second session as that user.
Preconditions:
- The target user has TOTP-based two-factor authentication enabled.
- The attacker is in a position to observe or intercept the TOTP code during a legitimate login (e.g., network-level interception, shoulder surfing, or a compromised client).
- The replay must occur within the TOTP validity period.
Security impact:
- Unauthorized account access by replaying a captured one-time code.
- Potential compromise of threat-intelligence data and administrative functions accessible to the targeted user.
Affected versions: <v2.5.48.
CVE-2026-103664NONE
EPSS 0.3%
MISP contains a reflected cross-site scripting (XSS) vulnerability in the analyst data notes panel. The seed path parameter, supplied by the user via the URL, was passed directly into inline JavaScript within the rendered HTML response without any sanitization or type enforcement.
An attacker who can convince an authenticated MISP user to navigate to a crafted URL (for example, via a phishing link) can inject arbitrary JavaScript that executes in the victim's browser context. This may allow the attacker to read session tokens, manipulate the page, or perform actions on behalf of the victim.
Preconditions:
- The victim must be authenticated to MISP and access the analyst data view for an attribute or object.
- The attacker must supply a malicious seed value in the URL path.
Impact:
- Execution of arbitrary JavaScript in the victim's browser session.
- Potential theft of session credentials or sensitive data visible in the page.
- Manipulation of the analyst data interface.
Affected: MISP versions prior to the fix (commit 58925dbf0, post v2.5.48).
CVE-2026-103659NONE
EPSS 0.2%
MISP contains an authorization bypass in the event flattening feature. When a user requests an event with the flatten option enabled, the application removes the Object containment from the query and returns object attributes as top-level event attributes. In doing so, the object-level distribution and sharing-group access control check was not re-applied to those attributes.
As a result, a user who can view a community-distributed event could retrieve attributes belonging to organisation-only objects (distribution level 0) or objects restricted to a specific sharing group, even though the user's organisation does not have access to those objects. This constitutes an unauthorized disclosure of sensitive threat intelligence data.
A secondary issue was introduced by the initial remediation: the fix reused the full Object contain conditions (including soft-delete state) as the gate for flattened attributes, causing an event owner requesting deleted attributes to lose all attributes whose parent object was still live. The final fix isolates the distribution ACL condition as the sole gate.
Preconditions:
- An authenticated user with access to a community-distributed event
- The event contains at least one object with a distribution level or sharing group that restricts access beyond the event's own distribution
Impact:
- Unauthorized disclosure of attributes belonging to restricted objects
- Potential exposure of organisation-specific threat intelligence to other organisations
Affected versions: <2.5.48
CVE-2026-103858NONE
EPSS 0.2%
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
CVE-2026-103651NONE
EPSS 0.2%
MISP contains a vulnerability in its one-time password (OTP) authentication flow that allows replay of a consumed HOTP (paper) token and rewinding of the token counter.
The HOTP verification logic compared the submitted token against a counter value that was cached in the user's session at the time the password was entered, rather than against the authoritative counter stored in the database. Because the session-cached counter is not updated after a token is successfully consumed, an attacker who holds a valid session (password already submitted) can reuse a previously burned HOTP token. The stale cached counter still matches the replayed token, granting a second successful authentication and effectively rewinding the counter state.
Preconditions:
- The target user has HOTP (paper token) second-factor authentication enabled.
- The attacker possesses a valid session in which the password step has already been completed (the OTP step is pending).
- The attacker has access to at least one HOTP token value (e.g., a paper token list).
Security impact:
- Bypass of the second authentication factor, allowing unauthorized access to a user's MISP account.
- Corruption of the HOTP counter state, potentially invalidating subsequent legitimate tokens or enabling further replays.
Affected versions: <2.5.48.