CVE-2026-39843: Plane is an an open-source project management tool

Routine

HIGH 7.7UPGRADE

CVE-2026-39843 is a high-severity flaw (CVSS 7.7) affecting plane. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Plane is an an open-source project management tool. From 0.28.0 to before 1.3.0, the remediation of GHSA-jcc6-f9v6-f7jw is incomplete which could lead to the same full read Server-Side Request Forgery when a normal html page contains a link tag with an href that redirects to a private IP address is supplied to Add link by an authenticated attacker with low privileges. Redirects for the main page URL are validated, but not the favicon fetch path.

Why this priority

High severity
Public exploit reference

A fixed release or distro patch exists.

Risk facts

CVSS score	7.7 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	Low
User interaction	None
EPSS exploit chance	0.2% (top 84%)
CISA exploited list	No
Weakness	CWE-918
Published	2026-04-09
Last modified	2026-10-25

Publisher (CNA): GitHub, Inc. · Vendor: plane

Last updated 2026-10-25 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-04-09 16:16 UTCPublished CVE record published
2026-10-25 23:10 UTCUpdated Record last modified

plane plane UPGRADE

Affected: >= 0.28.0 and < 1.3.0

Fixed in: 1.3.0

Safe to downgrade to: a release before 0.28.0

1. Check installed version

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

2. UPGRADE to 1.3.0 (Debian / Ubuntu)

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

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade plane

Note

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

3. If no update is available yet, DOWNGRADE to a release before 0.28.0 (Debian / Ubuntu)

apt-cache madison plane sudo apt install plane=<VERSION_BEFORE_0.28.0> sudo apt-mark hold plane

3. If no update is available yet, DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list plane sudo dnf downgrade plane-<VERSION_BEFORE_0.28.0> sudo dnf versionlock add plane

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.

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-2026-39843?

plane: upgrade to 1.3.0. Exact commands for each OS are on this page.

Is CVE-2026-39843 being exploited?

CVE-2026-39843 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-2026-39843 affect?

CVE-2026-39843 affects plane. Severity is high (CVSS 7.7). Plane is an an open-source project management tool. From 0.28.0 to before 1.3.0, the remediation of GHSA-jcc6-f9v6-f7jw is incomplete which could lead to the same full read Server-Side Request Forgery when a normal html page contains a link

How urgent is CVE-2026-39843?

Priority 36/100. High severity; Public exploit reference

References

← Back to latest CVEs