What is CVE-2026-5090?

Template::Plugin::HTML versions through 3.102 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 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.

How severe is CVE-2026-5090?

CVE-2026-5090 has a CVSS 3.x base score of 6.1, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is low, integrity low, and availability none.

Is CVE-2026-5090 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (20th percentile), an estimate of the probability of exploitation in the next 30 days.

How do I fix CVE-2026-5090?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

Does CVE-2026-5090 have an EU (EUVD) identifier?

Yes. CVE-2026-5090 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-30995.

When was CVE-2026-5090 published?

CVE-2026-5090 was published on 2026-05-19 and last updated on 2026-06-17.

CVE-2026-5090

CVE-2026-5090 is a medium-severity vulnerability with a CVSS 3.x base score of 6.1. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-79.

Key facts

Severity: Medium (CVSS 3.x base score 6.1)
EPSS exploit prediction: 0% (20th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-30995
Weakness: CWE-79
Published: 2026-05-19
Last modified: 2026-06-17

Description

Template::Plugin::HTML versions through 3.102 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.

Frequently asked questions

What is CVE-2026-5090?: Template::Plugin::HTML versions through 3.102 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.
How severe is CVE-2026-5090?: CVE-2026-5090 has a CVSS 3.x base score of 6.1, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is low, integrity low, and availability none.
Is CVE-2026-5090 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (20th percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2026-5090?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2026-5090 have an EU (EUVD) identifier?: Yes. CVE-2026-5090 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-30995.
When was CVE-2026-5090 published?: CVE-2026-5090 was published on 2026-05-19 and last updated on 2026-06-17.

References

Other CWE-79 (Cross-site Scripting (XSS)) vulnerabilities

CVE-2025-49410 — Critical (CVSS 10.0): Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in Imran Emu TC…
CVE-2024-47875 — Critical (CVSS 10.0): DOMPurify is a DOM-only, super-fast, uber-tolerant XSS sanitizer for HTML, MathML and SVG. DOMpurify was vulnerable to…
CVE-2024-6886 — Critical (CVSS 10.0): Improper Neutralization of Input During Web Page Generation (XSS or 'Cross-site Scripting') vulnerability in Gitea…
CVE-2023-45144 — Critical (CVSS 10.0): com.xwiki.identity-oauth:identity-oauth-ui is a package to aid in building identity and service providers based on…
CVE-2023-45138 — Critical (CVSS 10.0): Change Request is an pplication allowing users to request changes on a wiki without publishing the changes directly.…
CVE-2022-4361 — Critical (CVSS 10.0): Keycloak, an open-source identity and access management solution, has a cross-site scripting (XSS) vulnerability in the…

Browse all CWE-79 (Cross-site Scripting (XSS)) vulnerabilities →