CVE-2026-34590: Postiz is an AI social media scheduling tool

Q: How do I fix CVE-2026-34590?

postiz: upgrade to 2.21.4. Exact commands for each OS are on this page.

Q: Is CVE-2026-34590 being exploited?

CVE-2026-34590 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-2026-34590 affect?

CVE-2026-34590 affects postiz. Severity is medium (CVSS 5.4). Postiz is an AI social media scheduling tool. Prior to version 2.21.4, the POST /webhooks/ endpoint for creating webhooks uses WebhooksDto which validates the url field with only @IsUrl() (format check), missing the @IsSafeWebhookUrl valida

Q: How urgent is CVE-2026-34590?

Priority 27/100. Public exploit reference

Routine

MEDIUM 5.4UPGRADE

CVE-2026-34590 is a medium-severity flaw (CVSS 5.4) affecting postiz. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Postiz is an AI social media scheduling tool. Prior to version 2.21.4, the POST /webhooks/ endpoint for creating webhooks uses WebhooksDto which validates the url field with only @IsUrl() (format check), missing the @IsSafeWebhookUrl validator that blocks internal/private network addresses. The update (PUT /webhooks/) and test (POST /webhooks/send) endpoints correctly apply @IsSafeWebhookUrl. When a post is published, the orchestrator fetches the

Why this priority

Public exploit reference

A fixed release or distro patch exists.

Risk facts

CVSS score	5.4 (Medium)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	Low
User interaction	None
EPSS exploit chance	0.2% (top 87%)
CISA exploited list	No
Weakness	CWE-918
Published	2026-04-02
Last modified	2026-07-24

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

Last updated 2026-07-24 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-04-02 18:16 UTCPublished CVE record published
2026-07-24 21:10 UTCUpdated Record last modified

gitroom postiz UPGRADE

Affected: < 2.21.4

Fixed in: 2.21.4

Safe to downgrade to: no unaffected older release

1. Check installed version

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

2. UPGRADE to 2.21.4 (Debian / Ubuntu)

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

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade postiz

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-2026-34590?

postiz: upgrade to 2.21.4. Exact commands for each OS are on this page.

Is CVE-2026-34590 being exploited?

CVE-2026-34590 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-2026-34590 affect?

CVE-2026-34590 affects postiz. Severity is medium (CVSS 5.4). Postiz is an AI social media scheduling tool. Prior to version 2.21.4, the POST /webhooks/ endpoint for creating webhooks uses WebhooksDto which validates the url field with only @IsUrl() (format check), missing the @IsSafeWebhookUrl valida

How urgent is CVE-2026-34590?

Priority 27/100. Public exploit reference

Related CVEs

CVE-2026-40168 HIGH 8.2 UPGRADE Postiz is an AI social media scheduling tool
CVE-2026-40487 HIGH 8.9 UPGRADE Postiz is an AI social media scheduling tool
CVE-2026-42298 CRITICAL 10.0 UPGRADE Postiz is an AI social media scheduling tool
CVE-2026-34577 HIGH 8.6 UPGRADE Postiz is an AI social media scheduling tool
CVE-2026-34576 HIGH 7.7 UPGRADE Postiz is an AI social media scheduling tool

References

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