CVE-2026-49224

Executive Summary

CVE-2026-49224 is an authorization bypass vulnerability in Vvveb, an open-source Content Management System (CMS) with a built-in page builder, affecting all versions prior to 1.0.8.4. The flaw resides in the backend post revision operations, where the controller trusts caller-supplied identifiers without consistently applying the current authenticated user's scope, allowing a low-privileged Author account to access, restore, or delete revisions belonging to other Authors' posts. Successful exploitation enables reading sensitive draft content, overwriting another author's published content, and destroying audit trail records, with CVSS 3.1 base score of 8.3 (High) reflecting significant confidentiality and integrity impact. The vendor has issued a fix in version 1.0.8.4, but patch confirmation from tracked sources remains pending.

Technical Analysis

The vulnerability class is CWE-639: Authorization Bypass Through User-Controlled Key. The NVD description identifies the specific affected code path as the revision management system, located within the admin/controller/content/revisions.php controller and supported by the admin/sql/sqlite/post_content_revision.sql SQL queries. The core mechanism is a failure to enforce object-level authorization: the application trusts caller-controlled post_id, language_id, and created_at values when performing revision operations (list, read, restore, delete) without consistently applying the current authenticated user's admin_id as a filter clause.

In a proper implementation, revision operations should be scoped by both the post's ownership and the requesting user's identity — e.g., a SQL query should include WHERE post_id = ? AND admin_id = ?. The described vulnerability suggests that one or more of these operations omit the admin_id predicate, or apply it inconsistently across the different operations (list vs. read vs. restore vs. delete). This means that while the user interface may only expose revision controls for posts the current Author owns, the underlying API endpoints or controller actions do not validate that the supplied post_id actually belongs to the authenticated Author. Any Author who can guess, enumerate, or observe another Author's post identifier can directly invoke these operations with that foreign post_id.

The attack surface is the administrative backend of Vvveb, accessible over the network (per CVSS AV:N). The preconditions are: a valid low-privileged Author account (PR:L) and no user interaction required (UI:N). The access control is scoped per-user (S:U — scope unchanged), meaning the vulnerability does not cross trust boundaries beyond the application's authorization model. The confidentiality impact is High (C:H) because historic post content, including unpublished drafts, can be read. The integrity impact is High (I:H) because a restored revision can overwrite live content authored by another user. The availability impact is Low (A:L) because the attacker can delete revision records, destroying audit history but not rendering the CMS inoperable.

The fact that the description explicitly calls out "revision lists, reads, restores, and deletes" as all being affected indicates the deficiency spans the entire revision CRUD surface, not a single operation. The description's phrase "without consistently applying the current admin_id" suggests that some operations may enforce the check while others do not — an attacker would map which operations are vulnerable and choose the least-protected path.

Exploitation Scenarios

The attack chain for CVE-2026-49224 is inferred from the vulnerability class and the specific operations named in the NVD description. No public PoC or exploit code has been confirmed, so the following steps are derived from the CWE-639 authorization bypass pattern applied to the described revision-management functionality.

Step 1 — Reconnaissance and Target Identification:
The attacker, operating as a legitimate low-privileged Author account, first identifies the Vvveb deployment's admin backend URL (commonly /admin). Using the normal CMS user interface, the attacker creates a post to learn the structure of the revision API and observes the URL/request format when listing their own revisions. This reveals the controller name (revisions.php) and the parameter names (post_id, language_id, created_at). The attacker then needs a target-victim post identifier. Common methods include: (a) viewing the site's public content and noting the post ID in URL slugs or HTML comments, (b) walking sequential post IDs since CMS auto-increment identifiers are predictable, or (c) using the site's search or sitemap to enumerate posts owned by other Authors.

Step 2 — Triggering the Authorization Flaw:
With a target post_id belonging to another Author, the attacker crafts an HTTP request to the revision controller, substituting the foreign post_id value where their own would normally appear. Because the controller does not consistently enforce admin_id scoping, the application processes the request as if the attacker were authorized to access that post's revisions. If any consistency check exists elsewhere in the stack, the attacker may also tamper with language_id or created_at parameters to align with the victim post's revision history metadata.

Step 3 — Payload and Execution:
No injection payload is required — this is a pure authorization logic flaw, not an injection vulnerability. The "payload" is simply the crafted request containing the unauthorized post_id. Depending on which operation the attacker targets:

• List/Read: Request the revision list or a specific revision content to exfiltrate draft text, ideas, or unpublished edits from the victim's posts.
• Restore: Select an old revision of the victim's post and invoke the restore action. The CMS will overwrite the victim's current live content with the older revision, causing defacement, data loss, or publication of stale or incorrect information on the public-facing site.
• Delete: Invoke the delete operation on one or all of the victim's revision records, destroying the edit-history audit trail and removing the ability to roll back to prior versions.

Step 4 — Post-Exploitation Impact:
The attacker can now: read every draft and historic version of posts owned by any Author in the system; alter published content integrity by restoring outdated revisions (potentially defacing the site or publishing erroneous data); and erase forensic evidence of their activity by deleting revision records. In a multi-tenant scenario where the CMS hosts content for different departments or clients, the blast radius expands to cross-tenant data exposure and tampering.

Impact Assessment

Business Impact: Vvveb is marketed as a CMS for building websites, blogs, and e-commerce stores, meaning it holds sensitive business content, marketing drafts, product descriptions, promotional plans, and potentially customer-facing copy. The vulnerability allows an Author — typically a content contributor with limited trust — to read confidential draft material (confidentiality breach), modify the live content of other Authors without authorization (integrity breach that can deface the public site or publish incorrect pricing/product info), and delete revision history (audit/compliance impact). For e-commerce deployments, unauthorized content modification can be leveraged for malicious redirection, SEO poisoning, or insertion of fraudulent information.

Affected Systems: All Vvveb installations running versions prior to 1.0.8.4, specifically those where multiple Authors share a single CMS instance. Single-author blogs are not realistically exploitable, as the attacker would need a second Author account. Multi-author corporate blogs, marketing platforms, and agency-managed sites are the highest-risk environments.

Blast Radius and CVSS Assessment: The CVSS vector (CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:L) yields a base score of 8.3 (High). The key contributors are: network exploitability with low attack complexity requiring only low privileges; High confidentiality impact from draft exposure; High integrity impact from forced revision restoration; and Low availability impact from revision deletion. The scope is unchanged (S:U), meaning the compromise does not extend beyond the CMS's authorization boundary, though within that boundary the impact is severe. The EPSS score has not yet been published by FIRST.org, and the CISA KEV catalog does not list this CVE, indicating no confirmed in-the-wild exploitation as of the report date.

Detection Guidance

The following detection content targets the network and log signatures of the authorization bypass. Because the flaw is logic-based rather than payload-injection-based, detection relies on anomalous request patterns towards the revision controller, especially cross-user identifier usage.

Sigma Rule

title: Vvveb Revision Authorization Bypass - Cross-User Post Access
id: 3f4a9c8e-7b2d-4e5f-9a1c-6d8b2e4f1a0c
status: experimental
description: Detects attempts to access Vvveb backend revision operations with post_id values that likely belong to another author, indicating CVE-2026-49224 exploitation.
logsource:
  category: webserver
  product: apache
  service: access
detection:
  selection:
    cs-method:
      - 'GET'
      - 'POST'
    cs-uri-query|contains:
      - 'admin/controller/content/revisions'
      - 'revisions.php'
    cs-uri-query|re: 'post_id=(?!\d+)\d+'
  filter_known_good:
    cs-username:  # Populate with legitimate author sessions
      - 'legit_author_1'
      - 'legit_author_2'
  condition: selection and not filter_known_good
level: high
falsepositives:
  - Legitimate admin users accessing revisions of other authors' posts (if such role exists)
  - CMS internal calls that pass post_id without username context
tags:
  - attack.t1190
  - cve.2026.49224
  - cwe.639

YARA Rule

rule vvveb_revision_authz_bypass_cve_2026_49224 {
    meta:
        author = "valtersit.com Threat Intel"
        description = "Detects request patterns targeting Vvveb revision controller with potential cross-author post_id"
        cve = "CVE-2026-49224"
        severity = "high"
        date = "2026-01-01"
    strings:
        $revision_path = "admin/controller/content/revisions.php" ascii wide nocase
        $param_post_id = "post_id=" ascii wide nocase
        $param_language = "language_id=" ascii wide nocase
        $action_restore = "action=restore" ascii wide nocase
        $action_delete = "action=delete" ascii wide nocase
    condition:
        uint16(0) == 0x0A0D or uint16(0) == 0x0D0A  // HTTP request
        and $revision_path
        and $param_post_id
        and (any of ($action_*))
}

Suricata IDS Rule

alert http any any -> $HOME_NET any (
    msg:"CVE-2026-49224 Vvveb Revision Authorization Bypass";
    flow:to_server,established;
    http.uri;
    content:"/admin/controller/content/revisions";
    http.uri;
    content:"post_id=";
    http.uri;
    pcre:"/post_id=\d+/i";
    http.server;
    content:"Vvveb";
    classtype:attempted-admin;
    sid:202649224;
    rev:1;
    metadata:created_at 2026-01-01, updated_at 2026-01-01, cve CVE-2026-49224;
)

Elastic Detection

query: |
  event.category: web AND
  http.request.method: (GET or POST) AND
  http.request.uri: (*revisions* OR *post_content_revision*) AND
  http.request.uri: *post_id=* AND
  NOT user.name: admin

Elastic EQL:

sequence by source.ip
  [ web where http.request.method in ("GET","POST") and
    http.request.uri like "*revisions.php*" and
    http.request.uri like "*post_id=*" ]
  [ web where http.response.status_code == 200 and
    http.response.bytes > 1000 ] /* Success with substantial content suggests data exfiltration */

Splunk SPL Query

index=web sourcetype=access_combined
| eval is_revision=if(match(uri, "revisions(\.php)?"), 1, 0)
| eval has_post_id=if(match(uri, "post_id=\d+"), 1, 0)
| where is_revision=1 AND has_post_id=1
| stats count by src_ip, uri, status, user
| where count > 5 AND user != "admin"
| table _time, src_ip, uri, status, user, count
| sort - _time

Wazuh OSSEC Rule

<group name="vvveb,">
  <rule id="100492" level="12">
    <decoded>
      <program_name>apache|nginx</program_name>
    </decoded>
    <field name="url">revisions</field>
    <field name="url">post_id=</field>
    <description>Vvveb CVE-2026-49224: Author attempting cross-user revision access on /admin/controller/content/revisions.php</description>
    <group>cve-2026-49224,</group>
    <mitre>
      <id>T1190</id>
    </mitre>
  </rule>
</group>

Mitigation & Patch Guidance

Patch Confidence: 0/4 — UNPATCHED (no patch evidence from any tracked source).

The NVD description asserts the fix is delivered in version 1.0.8.4, but no patch sources (vendor advisory, commit reference, package changelog) have been confirmed by tracking systems at the time of writing. Treat the environment as vulnerable until the upgrade is verified against the vendor's official release channel.

1) Immediate Mitigations:

• Restrict Author accounts: Minimize the number of Authors to only trusted personnel. Consider converting Authors to a read-only role until patched.
• Enable multi-factor authentication (MFA) for all backend accounts to raise the bar for Author account compromise.
• Network-level restriction: Apply IP allowlisting to the /admin path via WAF or reverse proxy, limiting admin access to VPN or trusted office IP ranges.
• Harden the admin session: Ensure short session timeouts and verify that session tokens are not exposed in URLs or logs.
• If feasible, disable revision functionality temporarily by removing or blocking access to the revisions.php path in the web server config (e.g., location ~ ^/admin/controller/content/revisions.php { deny all; } in nginx, or equivalent .htaccess rule), accepting the loss of rollback capability as a trade-off.

2) Patch / Upgrade Steps:

• Monitor the official Vvveb repository and release feeds for version 1.0.8.4 or later.
• Prior to patching, back up the entire application and database — particularly the post_content_revision table — to preserve audit history.
• Upgrade to version 1.0.8.4. After upgrade, verify the fix by: (a) creating two Author accounts, (b) having each create a post with revisions, (c) attempting to list/restore/delete the other Author's revisions from the second account, and (d) confirming the operations are rejected with a 403 or similar authorization error.
• Confirm the upgrade in the CMS admin panel and check the changelog for explicit CVE-2026-49224 reference.

3) Long-Term Hardening:

• Adopt an object-level authorization framework: The root cause is manual, per-query admin_id scoping. The vendor should centralize authorization into an interceptor/middleware that binds any post_id to the session's user before controller actions execute.
• Implement parameter validation: Every controller action should validate that post_id, language_id, and created_at correspond to objects the authenticated user owns, not merely that the IDs are syntactically valid.
• Add audit logging: Even after patching, log all revision operations with the acting user's ID to enable forensic analysis if similar flaws resurface.
• Periodic security review: CMSes with custom controllers and raw SQL (as evidenced by the .sql file in the description) benefit from regular code audits focused on authorization logic.

References

1. NVD Entry: https://nvd.nist.gov/vuln/detail/CVE-2026-49224 — Official CVE record with description, CVSS vector, and CWE classification.
2. Vvveb Official Website: https://www.vvveb.com — Vendor site for version release information (1.0.8.4 fix).
3. Vvveb GitHub Repository: https://github.com/givanz/Vvveb — Source repository where the fix commit for version 1.0.8.4 should be reviewed.
4. CWE-639 Reference: https://cwe.mitre.org/data/definitions/639.html — MITRE's description of Authorization Bypass Through User-Controlled Key.
5. CISA Known Exploited Vulnerabilities Catalog: https://www.cisa.gov/known-exploited-vulnerabilities-catalog — CVE-2026-49224 is NOT currently listed; verify periodically for updates.

Threat Actor Activity: As of the report date, there is no public evidence of exploitation in the wild, no PoC or exploit code has been published, and no threat actor campaigns have been attributed to this CVE. The EPSS score has not yet been assigned by FIRST.org. Organizations should nonetheless patch promptly given the low complexity of the vulnerability class and the High CVSS score.