CVE-2025-6851
published 2025-07-11CVE-2025-6851: The Broken Link Notifier plugin for WordPress is vulnerable to Server-Side Request Forgery in all versions up to, and including, 1.3.0 via the ajax_blinks()…
PriorityP277medium6.5CVSS 3.1
AVNACLPRNUINSUCLILAN
ITWEXPLOITVulnCheck KEV
Exploited in the wild
EPSS
0.62%
45.3th percentile
The Broken Link Notifier plugin for WordPress is vulnerable to Server-Side Request Forgery in all versions up to, and including, 1.3.0 via the ajax_blinks() function which ultimately calls the check_url_status_code() function. This makes it possible for unauthenticated attackers to make web requests to arbitrary locations originating from the web application and can be used to query and modify information from internal services.
Affected
5 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| apos37 | broken_link_notifier | <= 1.3.0 | — |
| msrc | azl3_openjpeg2_2.3.1-12_on_azure_linux_3.0 | — | — |
| msrc | azure_linux_3.0_arm | — | — |
| msrc | azure_linux_3.0_x64 | — | — |
| pluginrx | broken_link_notifier | < 1.3.1 | 1.3.1 |
Detection & IOCsextracted from sources · hover to see the quote
otheraction=blnotifier_blinks&nonce={{nonce}}&source_url=http://test&header_links[]=http://{{interactsh-url}}&↗
- →Detect exploitation attempts by monitoring POST requests to /wp-admin/admin-ajax.php with the parameter action=blnotifier_blinks from unauthenticated users (no valid session/auth cookie). ↗
- →Presence of the string 'blnotifier_front_end' in page body indicates the vulnerable plugin is installed and active; use this as a fingerprint for asset discovery. ↗
- →Successful SSRF exploitation response contains the strings 'notify', 'timing', and 'Results were generated in' in the response body with HTTP 200 status. ↗
- →The nonce value required for the SSRF attack is leaked unauthenticated from the front-end page body via the pattern: blnotifier_front_end.*"nonce":"(.*?)" ↗
- →The X-Requested-With: xmlhttprequest header is used in the exploit request; filter for this header combined with the blnotifier_blinks action on admin-ajax.php. ↗
- →The SSRF is triggered via the header_links[] POST parameter, which is passed to check_url_status_code(); monitor for out-of-band DNS/HTTP callbacks when this parameter contains external or internal URLs. ↗
- ·The exploit requires a valid nonce extracted from the front-end page; the nonce is publicly accessible to unauthenticated users, making this a zero-authentication SSRF. ↗
- ·The vulnerability affects all plugin versions up to and including 1.3.0; version 1.3.1 is the first patched release. ↗
CVSS provenance
nvdv3.16.5MEDIUMCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
vulncheck7.2HIGH
vendor_msrc8.8HIGH
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GHSA
GHSA-x4vc-m5g5-663m: The Broken Link Notifier plugin for WordPress is vulnerable to Server-Side Request Forgery in all versions up to, and including, 1
ghsa_unreviewed·2025-07-11
CVE-2025-6851 [HIGH] CWE-918 GHSA-x4vc-m5g5-663m: The Broken Link Notifier plugin for WordPress is vulnerable to Server-Side Request Forgery in all versions up to, and including, 1
The Broken Link Notifier plugin for WordPress is vulnerable to Server-Side Request Forgery in all versions up to, and including, 1.3.0 via the ajax_blinks() function which ultimately calls the check_url_status_code() function. This makes it possible for unauthenticated attackers to make web requests to arbitrary locations originating from the web application and can be used to query and modify information from internal services.
VulnCheck
pluginrx broken_link_notifier Server-Side Request Forgery (SSRF)
vulncheck·2025·CVSS 7.2
CVE-2025-6851 [HIGH] pluginrx broken_link_notifier Server-Side Request Forgery (SSRF)
pluginrx broken_link_notifier Server-Side Request Forgery (SSRF)
The Broken Link Notifier plugin for WordPress is vulnerable to Server-Side Request Forgery in all versions up to, and including, 1.3.0 via the ajax_blinks() function which ultimately calls the check_url_status_code() function. This makes it possible for unauthenticated attackers to make web requests to arbitrary locations originating from the web application and can be used to query and modify information from internal services.
Affected: PluginRx Broken Link Notifier plugin for WordPress
Required Action: Apply remediations or mitigations per vendor instructions or discontinue use of the product if remediation or mitigations are unavailable.
Exploitation References: https://patchstack.com/database/wordpress/plugin/broken-
Microsoft
opj_t1_clbl_decode_processor in openjp2/t1.c in OpenJPEG 2.3.1 through 2020-01-28 has a heap-based buffer overflow in the qmfbid==1 case a different issue than CVE-2020-6851.
vendor_msrc·2020-01-14·CVSS 8.8
CVE-2020-8112 [HIGH] CWE-787 opj_t1_clbl_decode_processor in openjp2/t1.c in OpenJPEG 2.3.1 through 2020-01-28 has a heap-based buffer overflow in the qmfbid==1 case a different issue than CVE-2020-6851.
opj_t1_clbl_decode_processor in openjp2/t1.c in OpenJPEG 2.3.1 through 2020-01-28 has a heap-based buffer overflow in the qmfbid==1 case a different issue than CVE-2020-6851.
FAQ: Is Azure Linux the only Microsoft product that includes this open-source library and is therefore potentially affected by this vulnerability?
One of the main benefits to our customers who choose to use the Azure Linux distro is the commitment to keep it up to date with the most recent and most secure versions of the open source libraries with which the distro is composed. Microsoft is committed to transparency in this work which is why we began publishing CSAF/VEX in October 2025. See this blog post for more information. If impact to additional products is identified, we will update the CVE to reflect this.
Mar
No detection rules found.
Nuclei
WordPress Broken Link Notifier < 1.3.1 - Unauthenticated SSRF
nuclei·CVSS 6.5
CVE-2025-6851 [MEDIUM] WordPress Broken Link Notifier < 1.3.1 - Unauthenticated SSRF
WordPress Broken Link Notifier < 1.3.1 - Unauthenticated SSRF
The Broken Link Notifier plugin for WordPress is vulnerable to Server-Side Request Forgery in all versions up to, and including, 1.3.0 via the ajax_blinks() function which ultimately calls the check_url_status_code() function. This makes it possible for unauthenticated attackers to make web requests to arbitrary locations originating from the web application and can be used to query and modify information from internal services.
Template:
id: CVE-2025-6851
info:
name: WordPress Broken Link Notifier < 1.3.1 - Unauthenticated SSRF
author: iamnoooob,pdresearch
severity: high
description: |
The Broken Link Notifier plugin for WordPress is vulnerable to Server-Side Request Forgery in all versions up to, and including, 1.3.0 via t
No writeups or analysis indexed.
2025-07-11
Published
Exploited in the wild