8.3

CVE-2026-71573: Joomla! Core - [20260802] - Improper CORS origin validation in Joomla 4.0.0-5.4.7, 6.0.0-6.1.2

Analyzed
Published 18-08-2026Last modified 19-08-2026

Vulnerability summary

CVE-2026-71573 is a high (CVSS 8.3) CRLF Injection vulnerability in joomla! project joomla! cms. EPSS estimates a 0.34% chance of exploitation in the next 30 days, higher than 26.4% of scored vulnerabilities.

Overall risk
33/100
0100
Medium · default modelHow is this calculated?
CVSS score
8.3/10
010
High · v3.1 (NVD)
EPSS score
0.34%
0%100%
Low · +0.09 pp in 30 days
KEVNot listedNot listed by any tracked catalog.
RansomwareNot flaggedNo ransomware use recorded.
Public exploits0No public exploits recorded

Timeline

  1. 18-08-2026
    PublishedVulnerability first disclosed.
  2. 19-08-2026
    Last modifiedVulnerability information updated.

Description

Joomla! Core - [20260802] - Improper CORS origin validation in Joomla 4.0.0-5.4.7, 6.0.0-6.1.2 - An improper implementation prevented configured CORS origins from being properly validated in CORS requests.

CVSS metrics

3 scores · 2 sources · 2 versions

EPSS trend

Probability

0.34%

Chance of exploitation in the next 30 days

Percentile

26%

Versus all other CVEs

30-day change

Increase +0.09 pp

From 0.25% on 22-09-2026

22-09-202622-10-2026

Known exploited

Compare KEV catalogs
CISA KEV

Not in the CISA KEV catalog.

ENISA CNW

Not in the ENISA CNW catalog.

CIRCL

Not in the CIRCL catalog.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Joomla1 product
  • joomla\!≥ 4.0.0, < 5.4.8 | ≥ 6.0.0, < 6.1.3
Joomla! project1 product

2 vendors · 2 products

References

2 links