CVE-2026-27707: Seerr is an open-source media request and discovery manager for Jellyfin, Plex, and Emby

This week

HIGH 7.3REMOTEUPGRADE

CVE-2026-27707 is a high-severity flaw (CVSS 7.3) affecting seerr. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Seerr is an open-source media request and discovery manager for Jellyfin, Plex, and Emby. Starting in version 2.0.0 and prior to version 3.1.0, an authentication guard logic flaw in `POST /api/v1/auth/jellyfin` allows an unauthenticated attacker to register a new Seerr account on any Plex-configured instance by authenticating with an attacker-controlled Jellyfin server. The attacker receives an authenticated session and can immediately use the ap

Why this priority

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

A fixed release or distro patch exists.

Risk facts

CVSS score	7.3 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.6% (top 54%)
CISA exploited list	No
Weakness	CWE-288, CWE-807
Published	2026-02-27
Last modified	2026-06-17

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

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

Am I affected?

Timeline

2026-02-27 20:21 UTCPublished CVE record published
2026-06-17 10:27 UTCUpdated Record last modified

seerr seerr UPGRADE

Affected: >= 2.0.0 and < 3.1.0

Fixed in: 3.1.0

Safe to downgrade to: a release before 2.0.0

1. Check installed version

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

2. UPGRADE to 3.1.0 (Debian / Ubuntu)

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

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade seerr

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 2.0.0 (Debian / Ubuntu)

apt-cache madison seerr sudo apt install seerr=<VERSION_BEFORE_2.0.0> sudo apt-mark hold seerr

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

dnf --showduplicates list seerr sudo dnf downgrade seerr-<VERSION_BEFORE_2.0.0> sudo dnf versionlock add seerr

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-2026-27707?

seerr: upgrade to 3.1.0. Exact commands for each OS are on this page.

Is CVE-2026-27707 being exploited?

CVE-2026-27707 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-2026-27707 affect?

CVE-2026-27707 affects seerr. Severity is high (CVSS 7.3). Seerr is an open-source media request and discovery manager for Jellyfin, Plex, and Emby. Starting in version 2.0.0 and prior to version 3.1.0, an authentication guard logic flaw in `POST /api/v1/auth/jellyfin` allows an unauthenticated att

How urgent is CVE-2026-27707?

Priority 47/100. High severity; Public exploit reference; Remotely exploitable, no login, no user action

Software pages

Jellyfin vulnerabilities

Related CVEs

CVE-2026-27793 MEDIUM 6.5 UPGRADE Seerr is an open-source media request and discovery manager for Jellyfin, Plex, and Emby
CVE-2026-27792 MEDIUM 5.4 UPGRADE Seerr is an open-source media request and discovery manager for Jellyfin, Plex, and Emby

References

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