CVE-2026-21853

AFFiNE: One-click Remote Code Execution through Custom URL Handling

HIGH
8.8
CVSS Score
Published: March 2, 2026 at 06:55 PM UTC
Updated: June 17, 2026 at 10:19 AM UTC
2 products affected across 2 vendorsAFFiNEAFFiNE

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Severity
HIGH8.8
Exploit prediction
EPSS 0.6%
SSVC
PoC

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 0.25.4
v < 0.25.4
Affected range stops below 0.25.4, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

SSVC — Action Prioritization

SSVCPoCNot automatableTotal impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

8.8HIGHGitHub_M
Attack Vector
NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
REQUIRED
Scope
UNCHANGED
Confidentiality
HIGH
Integrity
HIGH
Availability
HIGH
Vector?

Quick Info

StatusANALYZED
CWE
CWE-94

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