CVE-2026-49226

Executive Summary

CVE-2026-49226 is an authorization bypass vulnerability in Vvveb CMS, a website and blog management platform with a built-in page builder. The flaw affects all Vvveb deployments prior to version 1.0.8.4 and allows a low-privileged user (Author role) to access, duplicate, or delete posts owned by other Authors, potentially exposing private drafts and causing data loss or content corruption. With a CVSS score of 8.3 (High), this vulnerability is remotely exploitable without user interaction and requires only low-privilege credentials to trigger. The issue is confirmed fixed in Vvveb version 1.0.8.4.

Technical Analysis

The vulnerability resides in the Vvveb backend post-management functionality, specifically involving the interaction between server-side access control enforcement and client-supplied parameters. The NVD description identifies the vulnerable component as the admin/controller/content/posts.php controller — a PHP file responsible for handling content post operations in the administrative interface.

The core flaw is an authorization bypass categorized under CWE-639 (Authorization Bypass Through User-Controlled Key). The controller fails to enforce server-side ownership validation on several post operations. Specifically, the following weaknesses are identified:

1. Filter Parameter Injection: The controller accepts a filter[admin_id] parameter that allows the caller to replace the server-selected admin_id restriction. This is a classic direct object reference (IDOR) pattern where the application trusts caller-supplied identifiers to determine data ownership boundaries. Rather than deriving the admin_id from the authenticated session, the application substitutes it with the value provided in the request.

2. Unrestricted Post Identifier: The controller accepts a caller-controlled post_id parameter for two sensitive high-impact operations — duplicating posts and deleting posts. This allows an attacker to reference arbitrary post identifiers without verifying that the authenticated user owns those posts.

3. Inconsistent Database Enforcement: The admin/sql/sqlite/post.sql file — the SQLite database schema/query definitions for post operations — does not consistently enforce the post.admin_id ownership constraint. This indicates that even at the database query level, the application fails to filter posts by the authenticated user's identifier, compounding the application-layer weakness.

The combination of these flaws means that the application's server-side administrative controller, the caller-supplied parameters, and the underlying database queries all fail to maintain the ownership model that should restrict Authors to their own content. The vulnerability is network-exploitable (AV:N), requires low privileges (PR:L — an Author account), and requires no user interaction (UI:N). The scope is unchanged (S:U), but the impact on integrity (I:H) and availability (A:H) is rated High, with confidentiality impact (C:L) rated Low — reflecting that the primary damage is unauthorized modification and deletion of content rather than mass data disclosure.

Exploitation Scenarios

No public PoC is available for this vulnerability; the attack chain described below is inferred from the vulnerability class and NVD description.

Step 1 — Reconnaissance and Target Identification: An attacker with an Author-level account in a Vvveb CMS instance first identifies the target platform. Shodan queries for "Vvveb CMS" or "Vvveb admin" can locate exposed Vvveb administrative panels. The attacker authenticates with their legitimate low-privileged Author credentials (or obtains them through credential stuffing or phishing). Since the vulnerability requires only low privileges, the bar for entry is minimal.

Step 2 — Triggering the Authorization Bypass: The attacker manipulates the admin/controller/content/posts.php controller by injecting a filter[admin_id] parameter alongside their request. By substituting the server-derived admin_id with an arbitrary value (e.g., the ID of another author), the attacker defeats the ownership restriction. Alternatively, the attacker can directly provide target post_id values to the duplicate or delete operations without the controller validating ownership.

Step 3 — Payload Execution at Vulnerability-Class Level: In an IDOR/authorization-bypass scenario, the attack mechanism is simple HTTP request manipulation. The attacker crafts requests to the post controller that: (a) include a filter[admin_id] value pointing to a victim author's identifier to view or list their posts; (b) include a victim's post_id in a duplicate-post request to create unauthorized copies of restricted content; or (c) include a victim's post_id in a delete-post request to trigger content destruction. The underlying post.sql database interactions fail to enforce the post.admin_id constraint, so the manipulated parameters flow through to the database layer without filtering.

Step 4 — Post-Exploitation Impact: Depending on the operation performed, the attacker can: view post metadata including private drafts (confidentiality impact — Low because metadata, not necessarily bodies, is exposed), duplicate another author's posts (content pollution and confusion), or delete posts and related content (data loss and availability impact — High). The low confidentiality rating suggests the attacker primarily gains access to metadata such as post identifiers and status, while the high integrity and availability ratings reflect the destructive and content-corrupting capabilities.

Impact Assessment

The CVSS vector CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:H/A:H translates to a base score of 8.3, placing this in the High severity band. The key characteristics of impact are:

Confidentiality (C:L): An attacker can access post metadata and discover post identifiers belonging to other authors, including potentially private or draft posts. The informational exposure is limited but can leak content existence, publication status, and authorship details.

Integrity (I:H): The ability to duplicate posts belonging to other authors allows an attacker to inject unauthorized content into the CMS, potentially poisoning the content feed, creating confusion, or seeding malicious content under another author's name. This is a high-impact integrity violation.

Availability (A:H): The ability to delete arbitrary posts and related content can cause significant data loss, destroy draft content, and disrupt publishing operations. This directly impacts business continuity and content operations.

Business Impact: For organizations using Vvveb CMS for corporate blogs, e-commerce content, or documentation, this vulnerability enables content destruction, unauthorized content injection, and exposure of internal draft material. Multi-author environments with distinct content ownership requirements are most severely affected. The attack requires no user interaction and can be chained with other attacks (e.g., planting malicious content to distribute malware or phishing links through legitimate author accounts).

Blast Radius: Any Vvveb installation prior to 1.0.8.4 with multiple Author accounts is affected. Single-author deployments are not at risk since the flaw requires crossing author ownership boundaries.

Detection Guidance

Sigma Rule

title: Vvveb CMS Post Admin IDOR - CVE-2026-49226
id: 9c8a2f41-7e3d-4b2a-9f5c-1a8d3e5f7b29
status: experimental
description: Detects requests to Vvveb backend post controller with suspicious filter[admin_id] or post_id parameters indicating possible IDOR exploitation
references:
    - https://nvd.nist.gov/vuln/detail/CVE-2026-49226
author: Valters IT Security
date: 2026/02/15
logsource:
    category: webserver
    product: apache
    service: access
detection:
    selection_post_controller:
        cs-method: 'POST'
        cs-uri-query|contains: 'admin/controller/content/posts.php'
    selection_idor_filter:
        cs-uri-query|contains: 'filter[admin_id]='
    selection_post_id_operation:
        cs-uri-query|contains|any:
            - 'action=duplicate'
            - 'action=delete'
    condition: selection_post_controller and (selection_idor_filter or selection_post_id_operation)
level: medium
tags:
    - attack.tentative
    - cve.2026-49226
    - cwe.639

YARA Rule

rule CVE_2026_49226_Vvveb_IDOR
{
    meta:
        author = "Valters IT Security"
        description = "Detects Vvveb CMS source patterns containing vulnerable post controller access patterns"
        cve = "CVE-2026-49226"
        cwe = "CWE-639"
        date = "2026-02-15"
        reference = "https://nvd.nist.gov/vuln/detail/CVE-2026-49226"
    strings:
        $s1 = "admin/controller/content/posts.php" ascii wide
        $s2 = "filter[admin_id]" ascii wide
        $s3 = "post_id" ascii wide
        $s4 = "post.admin_id" ascii wide
        $s5 = "admin/sql/sqlite/post.sql" ascii wide
        $s6 = "action=duplicate" ascii wide
        $s7 = "action=delete" ascii wide
    condition:
        (uint16(0) == 0x5A4D or uint16(0) == 0x7F45) and  # PE or ELF binary header, or scan file content
        filesize < 5MB and
        2 of ($s*) and
        ($s1 or $s5)
}

Suricata IDS Rule

alert http any any -> $HOME_NET any (
    msg:"CVE-2026-49226 Vvveb CMS Post Authorization Bypass Attempt";
    flow:established,to_server;
    content:"admin/controller/content/posts.php";
    http.uri;
    pcre:"/filter\[admin_id\]=/Ui";
    nocase;
    sid:202649226;
    rev:1;
    reference:cve,2026-49226;
    reference:cwe,639;
    classtype:attempted-admin;
    metadata:created_at 2026_02_15, updated_at 2026_02_15;
)

alert http any any -> $HOME_NET any (
    msg:"CVE-2026-49226 Vvveb CMS Post Delete/Duplicate Attempt";
    flow:established,to_server;
    content:"admin/controller/content/posts.php";
    http.uri;
    pcre:"/(action=(duplicate|delete)&post_id=\d+|action=(duplicate|delete)\?post_id=\d+)/Ui";
    nocase;
    sid:202649227;
    rev:1;
    reference:cve,2026-49226;
    reference:cwe,639;
    classtype:attempted-admin;
    metadata:created_at 2026_02_15, updated_at 2026_02_15;
)

Elastic Detection

POST /_search
{
  "query": {
    "bool": {
      "filter": [
        { "term": { "event.category": "web" } }
      ],
      "must": [
        {
          "wildcard": {
            "http.request.uri.path": "*/admin/controller/content/posts.php"
          }
        },
        {
          "bool": {
            "should": [
              {
                "query_string": {
                  "default_field": "http.request.uri.query",
                  "query": "filter[admin_id]:*"
                }
              },
              {
                "query_string": {
                  "default_field": "http.request.uri.query",
                  "query": "action:(duplicate OR delete) AND post_id:*"
                }
              }
            ],
            "minimum_should_match": 1
          }
        }
      ]
    }
  }
}

Splunk SPL Query

index=web sourcetype=access_combined_w3c
| where like(uri_path, "%admin/controller/content/posts.php%")
| rex field=uri_query "filter\[admin_id\]=?(?<injected_admin_id>\d+)"
| rex field=uri_query "post_id=?(?<target_post_id>\d+)"
| rex field=uri_query "action=?(?<post_action>\w+)"
| eval suspicious = if(isnotnull(injected_admin_id) OR (isnotnull(target_post_id) AND (post_action=="delete" OR post_action=="duplicate")), "true", "false")
| where suspicious=="true"
| stats count by src_ip, uri_path, injected_admin_id, target_post_id, post_action, _time
| sort - _time
| table src_ip, _time, uri_path, injected_admin_id, target_post_id, post_action

Wazuh OSSEC Rule

<group name="web, cms, vvveb, idor,">
  <rule id="100226" level="10" frequency="8" timeframe="120">
    <if_sid>31100</if_sid>
    <match>admin/controller/content/posts.php</match>
    <regex>filter\[admin_id\]|action=(duplicate|delete).*post_id</regex>
    <description>CVE-2026-49226 attempt - Vvveb CMS post authorization bypass (filter[admin_id] and post operations)</description>
    <group>attack.idor,cwe.639,cve.2026-49226,</group>
    <mitre>
      <id>T1530</id>
    </mitre>
  </rule>

  <rule id="100227" level="12" frequency="15" timeframe="300">
    <if_sid>100226</if_sid>
    <regex>action=delete</regex>
    <description>Multiple likely CVE-2026-49226 delete attempts - possible mass content destruction</description>
    <group>attack.idor,cwe.639,cve.2026-49226,</group>
  </rule>
</group>

Mitigation & Patch Guidance

Patch Confidence: 0/4 — UNPATCHED in the tracked intelligence sources. Although the NVD description states the issue is fixed in version 1.0.8.4, our tracked patch sources have not yet confirmed or published the official patch, so assume the fix is available but not yet fully verified by our monitoring.

Immediate Mitigations (until patch is verified/applied):

1. Upgrade Vvveb to version 1.0.8.4 — According to the NVD description, this version contains the fix. If version 1.0.8.4 is available from the vendor, prioritize the upgrade.
2. Restrict Author privileges — If operationally feasible, assign untrusted content contributors to roles with even lower privileges, or disable new Author account creation until the patch is applied.
3. Web Application Firewall (WAF) rules — Deploy WAF rules to block requests to admin/controller/content/posts.php containing filter[admin_id] parameters or action=delete/action=duplicate combined with post_id parameters, as demonstrated in the Suricata rules above.
4. Monitor administrative access — Implement heightened logging and alerting for all backend post operations, especially delete and duplicate actions on posts.php, and correlate with source IPs not normally associated with administrative tasks.

Patch/Upgrade Steps:

1. Test the upgrade in a staging environment to verify that the 1.0.8.4 version resolves the authorization issues without breaking existing functionality.
2. Back up the database and all CMS content before upgrading.
3. Deploy the upgrade to production following the vendor's upgrade procedures specific to Vvveb.
4. Verify the patch by creating two test Author accounts and confirming that each cannot access, duplicate, or delete the other's posts through the documented vulnerability path.

Long-Term Hardening:

1. Adopt a least-privilege model — Restrict CMS access based on role needs; auditors should not have Author accounts, and Authors should require approval for delete operations.
2. Implement IDOR testing in CI/CD — Add automated security tests that attempt to manipulate user-controlled keys (post_id, admin_id) across privilege boundaries during the software development lifecycle.
3. Monitor CVE feeds — Subscribe to NVD and vendor advisories for Vvveb; version 1.0.8.4 should be treated as the minimum accepted baseline.
4. Maintain security logs — Retain web server access logs for at least 90 days to support forensic analysis if exploitation is suspected.

References

1. NVD Entry: CVE-2026-49226 — https://nvd.nist.gov/vuln/detail/CVE-2026-49226
2. CWE-639 — Authorization Bypass Through User-Controlled Key: https://cwe.mitre.org/data/definitions/639.html
3. Vvveb Official Site — https://vvveb.com (vendor site for version 1.0.8.4 release information and upgrade downloads)
4. MITRE ATT&CK T1530 — Data from Cloud Storage Object: https://attack.mitre.org/techniques/T1530/ (relevant to the authorization bypass allowing unauthorized data access)

Threat Actor Campaigns: No known threat actor campaigns, active exploitation in the wild, or CISA KEV listing exist for this CVE at the time of reporting. The vulnerability was disclosed/reserved, and public exploit code is not available. The short window between disclosure and this report suggests limited real-world exploitation; however, organizations running Vvveb should treat the risk as imminent given the low complexity of exploitation.