EUVD-2026-72391
GHSA-f9pm-gcpp-fwjp
Severity by source
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Network-reachable, no auth, no interaction; pure availability impact from CPU exhaustion; AttributesExtension requirement is operator config, not attacker-controlled AC factor.
Primary rating from Vendor (VulnCheck).
CVSS VectorVendor: VulnCheck
Lifecycle Timeline
6DescriptionCVE.org
commonmark versions from 1.5.0 before 2.8.4 contain a denial of service vulnerability in the Attributes extension where AttributesListener::findTargetAndDirection() performs quadratic-time sibling list scanning. Unauthenticated attackers can submit approximately 32 KB of repeated attribute blocks to cause parsing to take over 5 seconds, exhausting server resources.
Articles & Coverage 1
AnalysisAI
Quadratic-time algorithmic complexity in league/commonmark's Attributes extension exposes PHP applications to remote denial of service. AttributesListener::findTargetAndDirection() walks the entire sibling list for each attribute node when no left-side target exists, producing O(N²) parse time; a ~32 KB payload of repeated {#a} blocks (8,000 iterations) takes over 5 seconds to process. …
Unlock full vulnerability intelligence
- Risk assessment & exploitation conditions
- Attack chain visualization
- Remediation with exact patch versions
- Threat intelligence from 22 sources
- Personal watchlist & email alerts
Free forever · No credit card required
Attack ChainAIDerived
Hypothetical attack flow derived from CVE metadata
Vulnerability AssessmentAI
| Exploitation | AttributesExtension (League\CommonMark\Extension\Attributes\AttributesExtension) must be registered in the application's CommonMark environment - this is an opt-in, explicitly configured feature that applications must add to their extension list. … Additional conditions and limiting factors are described in the full assessment. |
| Risk Assessment | The CVSS 4.0 score of 8.7 (AV:N/AC:L/AT:N/PR:N/UI:N/VA:H) accurately captures the network-reachable, zero-prerequisite nature of the attack against affected deployments. … Full risk analysis with EPSS, KEV, and SSVC signal comparison available after sign-in. |
| Exploit Scenario | Full exploit scenario with step-by-step reproduction available after sign-in. |
| Remediation | Upgrade league/commonmark to version 2.9.0 or later via Composer (composer require league/commonmark:^2.9.0), which contains the fix at commit 2d4c0fafa62501be919262064cffa6d71687430b addressing the quadratic sibling walk. … Detailed patch versions, workarounds, and compensating controls in full report. |
Recommended ActionAI
Within 24 hours, audit all deployed PHP applications using league/commonmark with the Attributes extension enabled, prioritizing those that accept untrusted Markdown input through comments, submissions, or API endpoints. …
Sign in for detailed remediation steps and compensating controls.
Threat intelligence, references, and detailed analysis are available after sign-in.
In PHP versions 7.1.x below 7.1.33, 7.2.x below 7.2.24 and 7.3.x below 7.3.11 in certain configurations of FPM setup it
sapi/cgi/cgi_main.c in PHP before 5.3.12 and 5.4.x before 5.4.2, when configured as a CGI script (aka php-cgi), does not
(1) boardData102.php, (2) boardData103.php, (3) boardDataJP.php, (4) boardDataNA.php, and (5) boardDataWW.php in Netgear
The '/common/download_agent_installer.php' script in the Quest KACE System Management Appliance 8.0.318 is accessible by
ProjectSend versions prior to r1720 are affected by an improper authentication vulnerability. Rated critical severity (C
Roundcube Webmail contains a critical PHP object deserialization vulnerability (CVE-2025-49113, CVSS 9.9) that allows au
Util/PHP/eval-stdin.php in PHPUnit before 4.8.28 and 5.x before 5.6.3 allows remote attackers to execute arbitrary PHP c
Palo Alto Networks PAN-OS management web interface contains an authentication bypass allowing unauthenticated attackers
Nagios XI version xi-5.7.5 is affected by OS command injection. Rated high severity (CVSS 8.8), this vulnerability is re
Nagios XI version xi-5.7.5 is affected by OS command injection. Rated high severity (CVSS 8.8), this vulnerability is re
The get_referers function in /opt/ws/bin/sblistpack in Sophos Web Appliance before 3.7.9.1 and 3.8 before 3.8.1.1 allows
The Backup Migration plugin for WordPress is vulnerable to Remote Code Execution in all versions up to, and including, 1
Same weakness CWE-407 – Inefficient Algorithmic Complexity
View allSame technique Denial Of Service
View allShare
External POC / Exploit Code
Leaving vuln.today