PT-2026-67511 · Shlinkio · Shlink

Theodosis Paidakis · CVE-2026-18738 · Published 2026-08-03 · Updated 2026-08-03

Mitre

CVSS v3.1

4.7

Medium

Base vector

AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:N/A:N

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.

Fix

RCE

Weakness Enumeration

CWE-1236

Related Identifiers

CVE-2026-18738

Affected Products

Shlink

References · 4

• https://nvd.nist.gov/vuln/detail/CVE-2026-18738 · Security Note
• https://github.com/theopaid/CSV-formula-injection-in-visit-exports-shlink- · Vendor Advisory
• https://github.com/shlinkio/shlink · Note
• https://vulncheck.com/advisories/shlink-csv-formula-injection-via-visit-export-cli · Note