CVE-2026-5388

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Source
https://cve.org/CVERecord?id=CVE-2026-5388
Import Source
https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-5388.json
JSON Data
https://api.osv.dev/v1/vulns/CVE-2026-5388
Aliases
Published
2026-08-23T13:34:09Z
Modified
2026-08-28T11:30:55Z
Severity
  • 9.3 (Critical) CVSS_V4 - CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N CVSS Calculator
Summary
justhtml before 1.15.0 Multiple Security Issues
Details

justhtml before 1.15.0 contains multiple security issues in URL sanitization helpers (clean_url_value/clean_url_in_js_string), HTML serialization, Markdown passthrough (html_passthrough=True), and several custom sanitization-policy edge cases. Depending on configuration, an attacker can bypass sanitization to inject active HTML and JavaScript — for example via encoded javascript: URLs, backslash-based relative URLs resolved as remote hosts, markup-breaking programmatic element/attribute names or HTML comments, raw reintroduction through Markdown passthrough, or preserved

Database specific 
{
    "cna_assigner":  "VulnCheck",
    "cwe_ids":  [
        "CWE-20"
    ],
    "osv_generated_from":  "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/5xxx/CVE-2026-5388.json"
}
References

Affected packages

Git / github.com/emilstenstrom/justhtml

Affected ranges

Type
GIT
Repo
https://github.com/emilstenstrom/justhtml
Events
Introduced
0 Unknown introduced commit / All previous commits are affected
Fixed
c8161901e50de91ad7e09ede7baa158181ef466e
Database specific
Show details 
{
    "extracted_events":  [
        {
            "introduced":  "0"
        },
        {
            "fixed":  "1.15.0"
        }
    ],
    "source":  [
        "AFFECTED_FIELD",
        "DESCRIPTION"
    ]
}

Affected versions

v0.*
v0.1.0
v0.10.0
v0.11.0
v0.12.0
v0.13.0
v0.13.1
v0.14.0
v0.15.0
v0.16.0
v0.17.0
v0.18.0
v0.19.0
v0.2.0
v0.20.0
v0.21.0
v0.22.0
v0.23.0
v0.24.0
v0.25.0
v0.26.0
v0.27.0
v0.28.0
v0.29.0
v0.3.0
v0.30.0
v0.31.0
v0.32.0
v0.33.0
v0.34.0
v0.35.0
v0.36.0
v0.37.0
v0.38.0
v0.39.0
v0.4.0
v0.40.0
v0.5.0
v0.5.1
v0.5.2
v0.6.0
v0.7.0
v0.8.0
v0.9.0
v1.*
v1.0.0
v1.1.0
v1.10.0
v1.11.0
v1.12.0
v1.13.0
v1.14.0
v1.2.0
v1.3.0
v1.4.0
v1.5.0
v1.6.0
v1.7.0
v1.8.0
v1.9.0
v1.9.1

Database specific

source 
"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-5388.json"