Medium · CVSS 5.1CVE-2026-128637

Open Redirect in MISP Modules Website Login via Unvalidated next ParameterCVE-2026-128637

Answer in brief

CVE-2026-128637 records a Medium severity (CVSS 5.1) vulnerability in Open Redirect in MISP Modules Website Login via Unvalidated next Parameter. The current sources do not mark it as known exploited. The current feed maps misp/misp-modules (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Nov 13, 2026Updated Nov 13, 2026Source checked Nov 13, 2026First seen by HOL Nov 13, 2026Material review Nov 13, 2026

Upstream Advisory

Key facts

Risk: Medium · CVSS 5.1
Exploitation: Not marked as known exploited
Affected software: 1 mapped package or product
Fix availability: Not reported

Why this deserves its current priority

CVSS is 5.1. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps misp/misp-modules (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
misp/misp-modulesgeneric	>=0 <=3.1.4	Not reported

Recommended response

Check inventory. Check lockfiles and deployed manifests for misp/misp-modules.
Review the reported fix. Source-reported solution: The fix introduces a _safe_next_url() validation function that restricts post-login redirect destinations to local paths or same-host HTTP(S) URLs. Any target that is empty, contains backslashes, control characters, leading/trailing whitespace, an unrecognized scheme, a mismatched host, or a protocol-relative form is rejected and the user is redirected to the home page (/). Accepted same-host URLs are normalized to local paths (scheme and authority stripped) while preserving query strings and fragments, ensuring the Location header always contains a relative path. This eliminates the ability to redirect users to arbitrary external destinations after authentication.

Evidence timeline and material changes

Published upstream
Nov 13, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Nov 13, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Nov 13, 2026

Sources and claim methodology

GitHub security advisorygithub.com

Upstream source description

The MISP Modules website component contains an open redirect vulnerability in its login endpoint. The /login route accepted a user-supplied next query parameter and passed it directly to Flask's redirect() function without validating the destination. An attacker could craft a URL such as https://victim-host/login?next=https://attacker.example/phish and deliver it to a user (e.g., via email or a lookalike page). After the user successfully authenticated, the application issued a 302 redirect to the attacker-controlled external URL. This enables phishing attacks where a user, believing they are still on the legitimate MISP Modules site, may enter additional credentials or sensitive information on the attacker's page. It can also be used to obscure the true destination of a link, bypassing user trust in the legitimate domain. The vulnerability requires the victim to interact with the crafted URL and complete a login, but no prior authentication or special configuration is needed on the attacker's side. The affected component is the website sub-project of misp-modules, specifically the account blueprint in website/app/account/account.py. No version boundaries are specified in the patch metadata.

Quoted source text, attributed separately from HOL analysis.

Package

Affected range

Fixed version

misp/misp-modulesgeneric

>=0 <=3.1.4

Not reported

Recommended response

Check inventory. Check lockfiles and deployed manifests for misp/misp-modules.

Review the reported fix. Source-reported solution: The fix introduces a _safe_next_url() validation function that restricts post-login redirect destinations to local paths or same-host HTTP(S) URLs. Any target that is empty, contains backslashes, control characters, leading/trailing whitespace, an unrecognized scheme, a mismatched host, or a protocol-relative form is rejected and the user is redirected to the home page (/). Accepted same-host URLs are normalized to local paths (scheme and authority stripped) while preserving query strings and fragments, ensuring the Location header always contains a relative path. This eliminates the ability to redirect users to arbitrary external destinations after authentication.

Sources and claim methodology

Upstream source description

Quoted source text, attributed separately from HOL analysis.