CVE-2026-18738 MEDIUM

CVE-2026-18738: Shlink CSV Formula Injection via Visit Export CLI

Vendor Shlinkio
Product Shlink
Weakness CWE-1236
Published August 3, 2026
Last update August 4, 2026

CVSS base score

5.1/10
Attack vector Network
Attack complexity Low
Privileges required None
User interaction
Confidentiality
Integrity

CVSS vector

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N

What the vulnerability does

01Description

Shlink versions 5.0.0 through 5.1.5 contain a CSV formula injection vulnerability that allows unauthenticated remote attackers to plant spreadsheet formulas into exported visit data by supplying malicious values in User-Agent, Referer, or request path headers beginning with formula-triggering characters such as =, +, -, or @. Attackers can craft a single unauthenticated request against any short URL to embed DDE or WEBSERVICE formula payloads into CSV cells, which are then executed on an administrator's client machine when the exported CSV file is opened in a spreadsheet application that evaluates formulas.

Key dates

02Disclosure timeline

August 3, 2026 CVE published
August 4, 2026 Record updated