9.8

CVE-2026-78265: WordPress The Events Calendar plugin <= 6.17.2 - PHP Object Injection vulnerability

Deferred
Published 24-08-2026Last modified 25-08-2026

Vulnerability summary

CVE-2026-78265 is a critical (CVSS 9.8) Deserialization of Untrusted Data vulnerability in nexcess the events calendar. EPSS estimates a 0.56% chance of exploitation in the next 30 days, higher than 46.1% of scored vulnerabilities. Fixed in 6.17.3.

Overall risk
70/100
0100
High · default modelHow is this calculated?
CVSS score
9.8/10
010
Critical · v3.1 (CVE.org)
EPSS score
0.56%
0%100%
Low · +0.25 pp in 30 days
KEVNot listedNot listed by any tracked catalog.
RansomwareNot flaggedNo ransomware use recorded.
Public exploits0No public exploits recorded

Timeline

  1. 24-08-2026
    PublishedVulnerability first disclosed.
  2. 25-08-2026
    Last modifiedVulnerability information updated.

Description

Unauthenticated PHP Object Injection in The Events Calendar <= 6.17.2 versions.

CVSS metrics

3 scores · 3 sources · 1 version

EPSS trend

Probability

0.56%

Chance of exploitation in the next 30 days

Percentile

46%

Versus all other CVEs

30-day change

Increase +0.25 pp

From 0.31% 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

Nexcess1 product
Wordpress1 product
  • the-events-calendar≤ 6.17.2 (fixed in 6.17.3)

2 vendors · 2 products

References

2 links