CVE-2020-5616: [Calendar01], [Calendar02], [PKOBO-News01], [PKOBO-vote01], [Telop01], [Gallery01], [CalendarForm01], and [Lin

Q: How do I fix CVE-2020-5616?

calendar01: downgrade or apply the listed mitigation; calendar02: downgrade or apply the listed mitigation; calendarform01: upgrade to newer than 1.0.3. Exact commands for each OS are on this page.

Q: Is CVE-2020-5616 being exploited?

CVE-2020-5616 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-2020-5616 affect?

CVE-2020-5616 affects calendar01, calendar02, calendarform01. Severity is critical (CVSS 9.8). [Calendar01], [Calendar02], [PKOBO-News01], [PKOBO-vote01], [Telop01], [Gallery01], [CalendarForm01], and [Link01] [Calendar01] free edition ver1.0.0, [Calendar02] free edition ver1.0.0, [PKOBO-News01] free edition ver1.0.3 and earlier, [PK

Q: How urgent is CVE-2020-5616?

Priority 61/100. Critical severity; Remotely exploitable, no login, no user action

This week

CRITICAL 9.8REMOTEDOWNGRADEDOWNGRADEUPGRADE

CVE-2020-5616 is a critical-severity flaw (CVSS 9.8) affecting calendar01, calendar02, calendarform01. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

[Calendar01], [Calendar02], [PKOBO-News01], [PKOBO-vote01], [Telop01], [Gallery01], [CalendarForm01], and [Link01] [Calendar01] free edition ver1.0.0, [Calendar02] free edition ver1.0.0, [PKOBO-News01] free edition ver1.0.3 and earlier, [PKOBO-vote01] free edition ver1.0.1 and earlier, [Telop01] free edition ver1.0.0, [Gallery01] free edition ver1.0.3 and earlier, [CalendarForm01] free edition ver1.0.3 and earlier, and [Link01] free edition ver1.

Why this priority

Critical severity
Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	9.8 (Critical)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	3.1% (top 12%)
CISA exploited list	No
Weakness	CWE-287
Published	2020-08-04
Last modified	2026-06-17

Publisher (CNA): JPCERT/CC · Vendor: calendar01 project · calendar02 project · calendarform01 project · gallery01 project · link01 project · pkobo-news01 project

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

Am I affected?

Timeline

2020-08-04 02:15 UTCPublished CVE record published
2026-06-17 03:21 UTCUpdated Record last modified

calendar01 project calendar01 DOWNGRADE

Affected: 1.0.0

Fixed in: no fixed release known

Safe to downgrade to: a release before 1.0.0

1. Check installed version

apt-cache policy calendar01 || rpm -q calendar01 || calendar01 --version

2. No fixed release: DOWNGRADE to a release before 1.0.0 (Debian / Ubuntu)

apt-cache madison calendar01 sudo apt install calendar01=<VERSION_BEFORE_1.0.0> sudo apt-mark hold calendar01

2. No fixed release: DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list calendar01 sudo dnf downgrade calendar01-<VERSION_BEFORE_1.0.0> sudo dnf versionlock add calendar01

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

calendar02 project calendar02 DOWNGRADE

Affected: 1.0.0

Fixed in: no fixed release known

Safe to downgrade to: a release before 1.0.0

1. Check installed version

apt-cache policy calendar02 || rpm -q calendar02 || calendar02 --version

2. No fixed release: DOWNGRADE to a release before 1.0.0 (Debian / Ubuntu)

apt-cache madison calendar02 sudo apt install calendar02=<VERSION_BEFORE_1.0.0> sudo apt-mark hold calendar02

2. No fixed release: DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list calendar02 sudo dnf downgrade calendar02-<VERSION_BEFORE_1.0.0> sudo dnf versionlock add calendar02

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

calendarform01 project calendarform01 UPGRADE

Affected: <= 1.0.3

Fixed in: newer than 1.0.3

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy calendarform01 || rpm -q calendarform01 || calendarform01 --version

2. UPGRADE to newer than 1.0.3 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade calendarform01

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade calendarform01

Note

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

gallery01 project gallery01 UPGRADE

Affected: <= 1.0.3

Fixed in: newer than 1.0.3

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy gallery01 || rpm -q gallery01 || gallery01 --version

2. UPGRADE to newer than 1.0.3 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade gallery01

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade gallery01

Note

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

link01 project link01 DOWNGRADE

Affected: 1.0.0

Fixed in: no fixed release known

Safe to downgrade to: a release before 1.0.0

1. Check installed version

apt-cache policy link01 || rpm -q link01 || link01 --version

2. No fixed release: DOWNGRADE to a release before 1.0.0 (Debian / Ubuntu)

apt-cache madison link01 sudo apt install link01=<VERSION_BEFORE_1.0.0> sudo apt-mark hold link01

2. No fixed release: DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list link01 sudo dnf downgrade link01-<VERSION_BEFORE_1.0.0> sudo dnf versionlock add link01

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

pkobo-news01 project pkobo-news01 UPGRADE

Affected: <= 1.0.3

Fixed in: newer than 1.0.3

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy pkobo-news01 || rpm -q pkobo-news01 || pkobo-news01 --version

2. UPGRADE to newer than 1.0.3 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade pkobo-news01

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade pkobo-news01

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-2020-5616?

calendar01: downgrade or apply the listed mitigation; calendar02: downgrade or apply the listed mitigation; calendarform01: upgrade to newer than 1.0.3. Exact commands for each OS are on this page.

Is CVE-2020-5616 being exploited?

CVE-2020-5616 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-2020-5616 affect?

CVE-2020-5616 affects calendar01, calendar02, calendarform01. Severity is critical (CVSS 9.8). [Calendar01], [Calendar02], [PKOBO-News01], [PKOBO-vote01], [Telop01], [Gallery01], [CalendarForm01], and [Link01] [Calendar01] free edition ver1.0.0, [Calendar02] free edition ver1.0.0, [PKOBO-News01] free edition ver1.0.3 and earlier, [PK

How urgent is CVE-2020-5616?

Priority 61/100. Critical severity; Remotely exploitable, no login, no user action

Related CVEs

CVE-2021-20725 MEDIUM 6.1 UPGRADE Reflected cross-site scripting vulnerability in the admin page of [Calendar01] free edition ver1.0.1 and earli
CVE-2020-5615 HIGH 8.8 DOWNGRADE DOWNGRADE Cross-site request forgery (CSRF) vulnerability in [Calendar01] free edition ver1.0.0 and [Calendar02] free ed

References

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