CVE-2024-0855: The Spiffy Calendar WordPress plugin before 4.9.9 doesn't check the event_author parameter, and allows any use

Q: How do I fix CVE-2024-0855?

spiffy calendar: upgrade to 4.9.9. Exact commands for each OS are on this page.

Q: Is CVE-2024-0855 being exploited?

CVE-2024-0855 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2024-0855 affect?

CVE-2024-0855 affects spiffy calendar. Severity is medium (CVSS 5.3). The Spiffy Calendar WordPress plugin before 4.9.9 doesn't check the event_author parameter, and allows any user to alter it when creating an event, leading to deceiving users/admins that a page was created by a Contributor+.

Q: How urgent is CVE-2024-0855?

Priority 39/100. Public exploit reference; Remotely exploitable, no login, no user action

This week

MEDIUM 5.3REMOTEUPGRADE

CVE-2024-0855 is a medium-severity flaw (CVSS 5.3) affecting spiffy calendar. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

The Spiffy Calendar WordPress plugin before 4.9.9 doesn't check the event_author parameter, and allows any user to alter it when creating an event, leading to deceiving users/admins that a page was created by a Contributor+.

Why this priority

Public exploit reference
Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	5.3 (Medium)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.5% (top 59%)
CISA exploited list	No
Published	2024-02-27
Last modified	2026-06-17

Publisher (CNA): WPScan · Vendor: spiffyplugins

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2024-02-27 09:15 UTCPublished CVE record published
2026-06-17 06:54 UTCUpdated Record last modified

spiffyplugins spiffy calendar UPGRADE

Affected: < 4.9.9

Fixed in: 4.9.9

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy spiffy-calendar || rpm -q spiffy-calendar || spiffy-calendar --version

2. UPGRADE to 4.9.9 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade spiffy-calendar

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade spiffy-calendar

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2024-0855?

spiffy calendar: upgrade to 4.9.9. Exact commands for each OS are on this page.

Is CVE-2024-0855 being exploited?

CVE-2024-0855 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2024-0855 affect?

CVE-2024-0855 affects spiffy calendar. Severity is medium (CVSS 5.3). The Spiffy Calendar WordPress plugin before 4.9.9 doesn't check the event_author parameter, and allows any user to alter it when creating an event, leading to deceiving users/admins that a page was created by a Contributor+.

How urgent is CVE-2024-0855?

Priority 39/100. Public exploit reference; Remotely exploitable, no login, no user action

Software pages

WordPress vulnerabilities

Related CVEs

CVE-2024-45458 HIGH 7.1 UPGRADE Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in Spiffy P
CVE-2024-45457 MEDIUM 6.5 UPGRADE Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in Spiffy P
CVE-2024-38692 HIGH 7.6 UPGRADE Improper Neutralization of Special Elements used in an SQL Command ('SQL Injection') vulnerability in Spiffy P
CVE-2024-30427 MEDIUM 5.4 UPGRADE Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in Spiffy P
CVE-2023-49745 MEDIUM 6.5 UPGRADE Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in Spiffy P

References

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