CVE-2021-40509

Exploitation

Not assessed. CISA has not published an exploitation assessment for this record, and it is not in the KEV catalog. That is an absence of assessment, not a finding of no risk.

SSVC decision

Not assessed by CISA

EPSS probability

0.96% probability of exploitation activity in the next 30 days.

EPSS percentile

Ranks above 58.9% of scored records. A rank, not a probability.

NVD base score

5.4 (CVSS v3.x), scored by the NVD independently of the CNA.

NVD CVSS vector

CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N

NVD analysis status

Modified. NVD last modified this record on 2026-06-17.

Red Hat severity

No Red Hat rating. Red Hat rates the CVEs that affect its products.

Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.

Published

2021-09-04 19:20Z5 YR AGO

Last updated

2024-08-04 02:44Z2 YR AGO

Reserved

2021-09-04

Assigning CNA

mitre

Record state

PUBLISHED

Severity

Not rated by the issuing CNA

CNA CVSS vector

Not published by the issuing CNA

Weaknesses

• CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')Base

Data version

5.1

Document digest

a441dd93714e3a327d68e289729e4c48a086b1be8559bc4c89cb4bfc9a0e3532

• packetstormsecurity.comhttp://packetstormsecurity.com/files/164045/jforum-2.7.0-Cross-Site-Scripting.htmlx_refsource_MISC
• lists.openwall.nethttps://lists.openwall.net/full-disclosure/2021/09/03/7x_refsource_MISC
• sourceforge.nethttps://sourceforge.net/p/jforum2/code/934/x_refsource_MISC
• seclists.org20210907 Re: a xss vulnerability in Jforum 2.7.0http://seclists.org/fulldisclosure/2021/Sep/13mailing-listx_refsource_FULLDISC