CVE-20XX-?
agent?

CVE-2026-73321

7.1 HIGH 0.6% exploit odds No fix listed Denial of service Web app

What it is

XenForo before 2.3.13 contains an uncontrolled recursion vulnerability in the BBCode parser that allows authenticated attackers to cause persistent denial of service by submitting a post with deeply nested BBCode tags. Attackers can craft a single malicious post with sufficient nesting depth to exceed PHP's stack limit, causing fatal errors that repeatedly terminate PHP-FPM workers for all visitors rendering the affected thread.

At a glance

Exploitability
Can be exploited over the network with a low-privilege account. High risk of service disruption.
Exploit odds
0.6% chance of exploitation in the next 30 days (EPSS).
Fix
No patch or advisory is linked yet. Look at mitigations or restrict exposure.

Timeline

  1. ReservedThe CVE id was reserved by its CNA
  2. PublishedDisclosed publicly on CVE.org and NVD
  3. Last updatedMost recent change to the record

Why it ranks here

Details

Published
Last modified
Exploit probability
0.6% · EPSS, next 30 days
Weakness
CWE-674
Record status
Analyzed

Affected

Attack profile CVSS 4.0 · 7.1

Attack vector
Network
Complexity
Low
Attack requirements
None
Privileges needed
Low
User interaction
None
Confidentiality
None
Integrity
None
Availability
High
Raw vector

CVSS:4.0/AV:N/AC:L/AT:N/PR:L/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

Is it in your code?

Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.

Read https://cve-list.com/agent/cve/CVE-2026-73321.md and follow it. Check whether this project is affected by CVE-2026-73321. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

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References

NVD record · CVE.org record