CVE-2026-68750

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Source
https://cve.org/CVERecord?id=CVE-2026-68750
Import Source
https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-68750.json
JSON Data
https://api.test.osv.dev/v1/vulns/CVE-2026-68750
Aliases
Published
2026-08-06T14:50:20.284Z
Modified
2026-08-13T03:47:26.659981977Z
Severity
  • 8.2 (High) CVSS_V4 - CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N CVSS Calculator
Summary
Quadratic sibling re-flattening in the html_sanitize_ex traversal engine allows CPU-exhaustion denial of service
Details

Inefficient Algorithmic Complexity vulnerability in the traversal engine in rrrene htmlsanitizeex allows an unauthenticated remote attacker to exhaust server CPU and memory via a flat run of sibling elements in sanitized HTML. The list clause of HtmlSanitizeEx.Traverser.traverse/2 recurses on the tail of a sibling list and then evaluates List.flatten([head] ++ tail) over the already flattened result, so every one of n siblings copies and re-walks the entire remaining tail. The flattening is only needed for the rare case where scrub returns several replacement nodes for one node, but the cost is paid across the whole tail at every step, making traversal quadratic in sibling count.

The traverser sits on every public entry point, so no particular scrubber or configuration is required and the payload needs only allowed tags. A 160 KB body of 20,000 sibling elements occupies a scheduler for roughly 1.7 seconds, and the cost grows faster than the body does.

This issue affects htmlsanitizeex: from 0.3.1 before 1.5.3.

Database specific 
{
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/68xxx/CVE-2026-68750.json",
    "cna_assigner": "EEF",
    "unresolved_ranges": [
        {
            "source": "AFFECTED_FIELD",
            "extracted_events": [
                {
                    "introduced": "69ea11d61525c470b39b6860d024770d5573ff1f"
                },
                {
                    "fixed": "9f5ccedbed230930813f992a1e6906fcf485981e"
                }
            ]
        }
    ],
    "cwe_ids": [
        "CWE-407"
    ]
}
References

Affected packages

Git / github.com/rrrene/html_sanitize_ex

Affected ranges

Type
GIT
Repo
https://github.com/rrrene/html_sanitize_ex
Events
Introduced
088f92b18a4a3911a862b527d5eb3713f9abac24
Fixed
f25255c82a3c6034a57d934718e10c982d29fa31
Fixed
9f5ccedbed230930813f992a1e6906fcf485981e
Database specific
Show details 
{
    "source": [
        "CPE_RANGE",
        "REFERENCES"
    ],
    "cpe": "cpe:2.3:a:rrrene:htmlsanitizeex:*:*:*:*:*:*:*:*",
    "extracted_events": [
        {
            "introduced": "0.3.1"
        },
        {
            "fixed": "1.5.3"
        }
    ]
}

Affected versions

v0.*
v0.3.1
v1.*
v1.0.0
v1.0.1
v1.2.0
v1.4.1
v1.4.2
v1.4.3
v1.4.4
v1.5.0
v1.5.0-rc.0
v1.5.1
v1.5.2

Database specific

source 
"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-68750.json"