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GCVE-1-2026-20242 (CVE-2026-91857)

Vulnerability from gna-1 – Published: 2026-09-15 09:14 – Updated: 2026-09-15 09:14
VLAI
Title
MISP: State-changing actions accessible via GET request enabling CSRF
Summary
Affected versions of MISP expose several state-changing controller actions without restricting them to POST. The affected actions are:  - EventReportsController::purgeUnusedPictures()  - NoticelistsController::enableNoticelist()  - ServersController::removeOrphanedCorrelations()  - WorkflowsController::rebuildRedis() The patch adds allowMethod(['post']) to each action, preventing them from being triggered through ordinary GET requests. For purgeUnusedPictures(), the corresponding UI previously used $.get(). The fix converts that request to POST and supplies X-CSRF-Token, while the controller enables header-only CSRF validation for that AJAX action. Because GET requests can be induced cross-origin through links, images, redirects, or navigation, accepting GET for these state-changing operations can let an attacker trigger them using the authenticated victim's session. Version affected: ≤2.5.45
Severity
5.3 (Medium)
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:L/VA:L/SC:N/SI:N/SA:N
CWE
  • CWE-352 - Cross-Site Request Forgery (CSRF)
Assigner
GNA-1 This instance
References
Impacted products
Vendor Product Version CPE status
MISP MISP Affected: 0 , < 2.5.46 (semver)
guessed Create a notification for this product.
Credits
iglocska Claude Opus 5 (1M context)
GCVE extensions
AI involvement GCVE-BCP-05-X-01
Whole record AI-generated Review: review GNA-1

Draft vulnerability metadata was generated from a git-format patch using an Ollama-hosted language model. Human validation is required before publication.

ai-computer-assisted:llm-generatedai-computer-assisted:classification
Model Source Identifier
qwen3.8:27b ollama qwen3.8:27b
Patch provenance GCVE-BCP-05-X-02
Generator
patch2vuln.py on 2026-09-15 09:10
Model
qwen3.8:27b
Input
https://github.com/MISP/MISP/commit/b4a5486b5.patch adc31514b96a…
Confidence
high
Commit Subject Patch SHA-256
b4a5486b5ddd fix: [security] Require POST for four remaining adc31514b96a…
Fix summary

The vulnerability is remediated by restricting all four state-changing actions to accept only POST requests via the CakePHP allowMethod() guard. Additionally, the client-side JavaScript for purgeUnusedPictures is updated to issue a POST request with the page's CSRF token in the X-CSRF-Token header, and a beforeFilter() hook is added to EventReportsController to configure header-only CSRF token validation for that specific action, since it is invoked via hand-built AJAX rather than a rendered form.

Patch summary

Adds $this->request->allowMethod(['post']) to purgeUnusedPictures, enableNoticelist, removeOrphanedCorrelations, and rebuildRedis. Adds a beforeFilter() method to EventReportsController calling _csrfTokenHeaderOnly(['purgeUnusedPictures']) to permit CSRF token validation via the X-CSRF-Token header. Updates the managed_imported_pictures.ctp view to replace $.get() with $.ajax() using type 'post' and the X-CSRF-Token header. Adds REST response handling and flash/redirect logic to rebuildRedis for consistency with other actions.

CVSS rationale

AV:N: The attack is delivered over the network (e.g., a malicious link or page). AC:L: No special race conditions or complex setup are required; a simple GET URL suffices. AT:N: No prior compromise or manipulation of the target system is needed. PR:L: The attacker requires the victim to be an authenticated MISP user; the attacker themselves need not be authenticated. UI:A: The victim must actively interact (click a link or navigate to a crafted page) to trigger the forged request. VC:N: No confidential data is exposed by the affected actions. VI:L: Integrity impact is low; the actions cause limited state changes (deleting unused pictures, toggling a noticelist, removing orphaned correlations, rebuilding a cache) rather than corrupting critical data. VA:N: No meaningful availability impact; the actions do not cause denial of service. SC/SI/SA:N: No impact on subsequent systems.

Weakness rationale
  • CWE-352 The root cause is that state-changing endpoints accept GET requests, which are not protected by the framework's CSRF token mechanism. This allows an attacker to forge requests on behalf of an authenticated user via links, auto-loading resources, or other passive/active user interactions, which is the defining characteristic of CSRF.
Assumptions to verify
  • The fix commit is 196 commits before the v2.5.46 tag, implying the vulnerability existed in versions prior to v2.5.46; exact affected version range is not explicitly stated in the patch.
  • MISP requires user authentication to access the affected endpoints; the PR:L assumption is based on MISP's standard authentication model.
  • The CSRF token mechanism in CakePHP (the framework used by MISP) is assumed to protect POST requests but not GET requests, consistent with the patch's own comments.
  • The vulnerability was found during internal review and was not externally reported, per the commit message.
Model comparison

Selected qwen3.8:27b by deterministic-consensus-v1
The selected result is closest to model consensus; this heuristic does not establish factual correctness and human review remains required.

Model Score Agreement Confidence Assumptions
qwen3.8:27b 7 9 high 4
To clipboard 

{
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            "NoticelistsController",
            "ServersController",
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            "app/Controller/ServersController.php",
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            "app/View/EventReports/managed_imported_pictures.ctp"
          ],
          "repo": "https://github.com/MISP/MISP",
          "vendor": "MISP",
          "versions": [
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              "status": "affected",
              "version": "0",
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      ],
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              "value": "\u003cp\u003e\u003c/p\u003e\u003cp\u003eAffected versions of MISP expose several state-changing controller actions without restricting them to POST.\u003c/p\u003e\n\u003cp\u003eThe affected actions are:\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003ccode\u003e\u2003-\u0026nbsp;EventReportsController::purgeUnusedPictures()\u003c/code\u003e\n\u003cbr\u003e\u003ccode\u003e\u2003-\u0026nbsp;NoticelistsController::enableNoticelist()\u003c/code\u003e\n\u003cbr\u003e\u003ccode\u003e\u2003-\u0026nbsp;ServersController::removeOrphanedCorrelations()\u003c/code\u003e\n\u003cbr\u003e\u003cdiv\u003e\u003ccode\u003e\u2003- WorkflowsController::rebuildRedis()\u003c/code\u003e\u003c/div\u003e\u003cdiv\u003e\u003ccode\u003e\u003cbr\u003e\u003c/code\u003e\u003c/div\u003e\u003cp\u003e\u003ccode\u003e\u003c/code\u003e\u003c/p\u003e\u003cp\u003eThe patch adds \u003ccode\u003eallowMethod([\u0027post\u0027])\u003c/code\u003e to each action, preventing them from being triggered through ordinary GET requests.\u003c/p\u003e\n\u003cp\u003eFor \u003ccode\u003epurgeUnusedPictures()\u003c/code\u003e, the corresponding UI previously used \u003ccode\u003e$.get()\u003c/code\u003e. The fix converts that request to POST and supplies \u003ccode\u003eX-CSRF-Token\u003c/code\u003e, while the controller enables header-only CSRF validation for that AJAX action.\u003c/p\u003e\n\u003cp\u003eBecause GET requests can be induced cross-origin through links, images, redirects, or navigation, accepting GET for these state-changing operations can let an attacker trigger them using the authenticated victim\u0027s session.\u003c/p\u003e\u003cp\u003eVersion affected: \u22642.5.45\u003cbr\u003e\u003c/p\u003e\u003cp\u003e\u003c/p\u003e"
            }
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          "value": "Affected versions of MISP expose several state-changing controller actions without restricting them to POST.\n\n\nThe affected actions are:\n\n\n\n\u2003-\u00a0EventReportsController::purgeUnusedPictures()\n\n\u2003-\u00a0NoticelistsController::enableNoticelist()\n\n\u2003-\u00a0ServersController::removeOrphanedCorrelations()\n\n\u2003- WorkflowsController::rebuildRedis()\n\n\n\n\n\n\nThe patch adds allowMethod([\u0027post\u0027]) to each action, preventing them from being triggered through ordinary GET requests.\n\n\nFor purgeUnusedPictures(), the corresponding UI previously used $.get(). The fix converts that request to POST and supplies X-CSRF-Token, while the controller enables header-only CSRF validation for that AJAX action.\n\n\nBecause GET requests can be induced cross-origin through links, images, redirects, or navigation, accepting GET for these state-changing operations can let an attacker trigger them using the authenticated victim\u0027s session.\n\nVersion affected: \u22642.5.45"
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      "title": "MISP: State-changing actions accessible via GET request enabling CSRF",
      "x_gcve": [
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    "cveId": "CVE-2026-91857",
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Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

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Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.


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