Reverse Tabnabbing in showdown

Description

Versions of showdown prior to 1.9.1 are vulnerable to Reverse Tabnabbing. The package uses target='_blank' in anchor tags, allowing attackers to access window.opener for the original page when opening links. This is commonly used for phishing attacks.

Recommendation

Update the showdown package to the latest compatible version. Followings are version details:

• Affected version(s): < 1.9.1
• Patched version(s): 1.9.1

References

• GHSA-h6mq-3cj6-h738
• snyk.io
• www.npmjs.com
• CWE-1022

Related Issues

• @hpke/core reuses AEAD nonces - CVE-2025-64767
• Spoofing attack in swagger-ui - CVE-2018-25031
• MailDev Remote Code Execution - CVE-2024-27448
• vxe-table prototype pollution - CVE-2024-57080

Tags:

npm

showdown