What’s Vulnerable › Vulnerabilities

CVE-2026-5090: Template::Plugin::HTML versions before 3.103 for Perl allows HTML and JavaScript to be injected

• Severity: medium (CVSS 6.1 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.3% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-05-19 · updated 2026-09-19
• Weakness: CWE-79

Description

Template::Plugin::HTML versions before 3.103 for Perl allows HTML and JavaScript to be injected. The html_filter function did not escape single quotes. HTML attributes inside of single quotes could be have code injected. For example, the variable "var" in <a id='ref' title='[% var | html %]'> would not be properly escaped. An attacker could insert some limited HTML and JavaScript, for example, var = " ' onclick='while (true) { alert(1) }'" Note that arbitrary HTML and JavaScript would be difficult to inject, because angle brackets, ampersands and double-quotes would still be escaped.

References

• https://github.com/abw/Template2/issues/327
• https://github.com/cpan-authors/Template2/commit/ca539f49f6ffd1c2b7d9ef4f48f6b88292418734.patch
• https://metacpan.org/release/TODDR/Template-Toolkit-3.103/changes
• http://www.openwall.com/lists/oss-security/2026/05/19/40

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