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    "cveMetadata": {
        "cveId": "CVE-2026-85091",
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        "state": "PUBLISHED",
        "assignerShortName": "VulnCheck",
        "dateReserved": "2026-09-02T23:53:05.582Z",
        "datePublished": "2026-09-03T01:04:44.460Z",
        "dateUpdated": "2026-09-03T01:04:44.460Z"
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                "dateUpdated": "2026-09-03T01:04:44.460Z"
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            "datePublic": "2026-09-02T00:00:00.000Z",
            "title": "zlib 1.3.1.2 through 1.3.2 Heap Buffer Overflow via gz_vacate",
            "descriptions": [
                {
                    "lang": "en",
                    "value": "zlib versions 1.3.1.2 through 1.3.2 contain a heap buffer overflow vulnerability in the gz_vacate() function when processing non-blocking gzwrite() operations with stale external buffer pointers. Attackers can trigger the overflow by calling gzprintf() or gzvprintf() after a write stall, causing an unchecked memmove() to write beyond the internal input buffer boundary."
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            ],
            "problemTypes": [
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                    "descriptions": [
                        {
                            "lang": "en",
                            "description": "Out-of-bounds Write",
                            "cweId": "CWE-787",
                            "type": "CWE"
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            "affected": [
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                    "vendor": "zlib",
                    "product": "zlib",
                    "defaultStatus": "unaffected",
                    "packageURL": "pkg:github/madler/zlib",
                    "versions": [
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                            "version": "1.3.1.2",
                            "lessThanOrEqual": "1.3.2",
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                        "vectorString": "CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:N/VI:H/VA:H/SC:N/SI:N/SA:N",
                        "baseScore": 8.3,
                        "baseSeverity": "HIGH",
                        "attackVector": "NETWORK",
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                        "attackRequirements": "NONE",
                        "privilegesRequired": "NONE",
                        "userInteraction": "NONE",
                        "vulnConfidentialityImpact": "NONE",
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                        "scope": "UNCHANGED",
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                {
                    "url": "https://gist.github.com/thesmartshadow/e0b9481792afb7c31e86fee1ff084490",
                    "name": "Technical report and proof of concept",
                    "tags": [
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                    "url": "https://github.com/madler/zlib/blob/v1.3.2/gzwrite.c#L393",
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                    "url": "https://www.vulncheck.com/advisories/zlib-1.3.1.2-through-1.3.2-heap-buffer-overflow-via-gz-vacate"
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                {
                    "lang": "en",
                    "value": "Ali Firas (thesmartshadow)",
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