What’s Vulnerable › Vulnerabilities

CVE-2021-37746

• Severity: medium (CVSS 6.1 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 1.2% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2021-07-30 · updated 2026-06-17
• Weakness: CWE-601

Description

textview_uri_security_check in textview.c in Claws Mail before 3.18.0, and Sylpheed through 3.7.0, does not have sufficient link checks before accepting a click.

Affected products

• Claws-Mail: before 3.18.0 — fixed in 3.18.0
• Fedoraproject Fedora: 33, 34
• Sylpheed Project Sylpheed: through 3.7.0

How to fix

Upgrade to a fixed version: Claws-Mail 3.18.0. Check the vendor advisory for mitigations.

References

• https://claws-mail.org/download.php?file=releases/claws-mail-3.18.0.tar.xz
• https://git.claws-mail.org/?p=claws.git%3Ba=commit%3Bh=ac286a71ed78429e16c612161251b9ea90ccd431
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/L2QNUIWASJLPUZZKWICGCEGYJZCQE7NH/
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/RCJXHUSYHGVBSH2ULD7HNXLM7QNRECZ6/
• https://sylpheed.sraoss.jp/sylpheed/v3.7/sylpheed-3.7.0.tar.xz
• https://claws-mail.org/download.php?file=releases/claws-mail-3.18.0.tar.xz
• https://git.claws-mail.org/?p=claws.git%3Ba=commit%3Bh=ac286a71ed78429e16c612161251b9ea90ccd431
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/L2QNUIWASJLPUZZKWICGCEGYJZCQE7NH/
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/RCJXHUSYHGVBSH2ULD7HNXLM7QNRECZ6/
• https://sylpheed.sraoss.jp/sylpheed/v3.7/sylpheed-3.7.0.tar.xz

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