Secuno
ENNL
Book demo

CVE-2026-21853

Affine remote code execution

8.8 HIGHPublic exploitEPSS 0.62%
  1. Published2 Mar 2026

Description

AFFiNE is an open-source, all-in-one workspace and an operating system. Prior to version 0.25.4, there is a one-click remote code execution vulnerability. This vulnerability can be exploited by embedding a specially crafted affine: URL on a website. An attacker can trigger the vulnerability in two common scenarios: 1/ A victim visits a malicious website controlled by the attacker and the website redirect to the URL automatically, or 2/ A victim clicks on a crafted link embedded on a legitimate website (e.g., in user-generated content). In both cases, the browser invokes AFFiNE custom URL handler, which launches the AFFiNE app and processes the crafted URL. This results in arbitrary code execution on the victim’s machine, without further interaction. This issue has been patched in version 0.25.4.

CVSS 3.1 breakdown

Attack vectorNetwork
Attack complexityLow
Privileges requiredNone
User interactionRequired
ScopeUnchanged
ConfidentialityHigh
IntegrityHigh
AvailabilityHigh
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

Affected products

Affine< 0.25.4

Remediation

Fixed in
Affine≥ 0.25.4

References

Related CVEs

Recent high-severity vulnerabilities sharing a weakness type.

CVE-2026-891079.9
SAP S/4HANA (Manage Substitution/Validation Rules) does not sufficiently validate input…
CVE-2026-961199.9
IBM i 7.3, 7.4, 7.5, and 7.6 could allow a remote authenticated attacker to obtain…
CVE-2026-821088.8
IBM DataStage on Cloud Pak for Data 5.4.0.0 could allow a remote authenticated attacker…
CVE-2026-909209.8
IBM Maximo AI Service 9.1.0, and 9.2.0 could allow a remote attacker to execute…
CVE-2026-185378.7
IBM Maximo Application Suite - Location Service for Esri Component 9.2, 9.1, and 9.0 is…
CVE-2026-1093088.8
Craft CMS 4.0.0 before 4.18.7 and 5.0.0 before 5.10.14 passes the raw 'updates' request…

Frequently asked

Is CVE-2026-21853 being actively exploited?

CVE-2026-21853 is not in the CISA KEV catalog. A public exploit reference exists, so treat it as exploitable. Its EPSS exploit probability is 0.62%.

How severe is CVE-2026-21853?

CVE-2026-21853 has a CVSS 3.1 base score of 8.8, rated high. EPSS estimates a 0.62% probability of exploitation.

Which products are affected by CVE-2026-21853?

Affected products include Affine.

How do I fix CVE-2026-21853?

Upgrade affected software to a fixed version, for example Affine 0.25.4 or later, then confirm no affected versions remain in your inventory.

How Secuno handles this

Secuno correlates vulnerabilities like CVE-2026-21853 against the real software inventory on every managed device, every day. Rather than a static severity, each match is scored in context: exploit availability, EPSS, the asset's exposure, and business criticality decide where it lands in the queue. If an affected version is present anywhere across your portfolio, it surfaces automatically with a prioritised remediation path.

See how prioritisation worksBook a demo

Get Patch this first every Monday

Five vulnerabilities that matter this week, ranked on real exploitation. Plain language, one email, no spam.

You can unsubscribe with one click from every issue. We handle your details as described in our privacy policy.

Data from the NVD, CISA KEV catalog and FIRST EPSS. CVSS 3.1 base score shown where available.