CVE-2026-128321

{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-128321", "assignerOrgId": "37e5125f-f79b-445b-8fad-9564f167944b", "state": "PUBLISHED", "assignerShortName": "certcc", "dateReserved": "2026-11-13T00:02:00.631Z", "datePublished": "2026-11-13T00:08:32.021Z", "dateUpdated": "2026-11-13T02:05:51.969Z"}, "containers": {"cna": {"title": "Tight JPEG decoding in TightVNC and UltraVNC viewers contains a heap-based buffer overflow vulnerability", "descriptions": [{"lang": "en", "value": "Tight JPEG decoding in TightVNC and UltraVNC viewers contains a heap-based buffer overflow because an attacker-controlled framebuffer rectangle width is not validated against a fixed-size decoding buffer. A malicious VNC server can cause an out-of-bounds heap write when a user connects, resulting in application crash and potentially other memory-corruption impacts."}], "source": {"discovery": "UNKNOWN"}, "affected": [{"vendor": "UltraVNC", "product": "UltraVNC", "versions": [{"status": "affected", "version": "1.8.2.4", "lessThanOrEqual": "1.8.2.6", "versionType": "custom"}]}, {"vendor": "Glavsoft (TightVNC)", "product": "TightVNC", "versions": [{"status": "affected", "version": "1.3.10", "lessThanOrEqual": "1.3.10", "versionType": "custom"}]}], "problemTypes": [{"descriptions": [{"lang": "en", "description": "CWE-122 Heap-Based Buffer Overflow"}]}], "references": [{"url": "https://www.tightvnc.com/"}, {"url": "https://github.com/ultravnc/ultravnc"}], "x_generator": {"engine": "VINCE 4.0.3", "env": "prod", "origin": "https://cveawg.mitre.org/api/cve/CVE-2026-128321"}, "providerMetadata": {"orgId": "37e5125f-f79b-445b-8fad-9564f167944b", "shortName": "certcc", "dateUpdated": "2026-11-13T00:08:32.021Z"}}, "adp": [{"title": "CVE Program Container", "references": [{"url": "https://www.kb.cert.org/vuls/id/644655"}], "providerMetadata": {"orgId": "af854a3a-2127-422b-91ae-364da2661108", "shortName": "CVE", "dateUpdated": "2026-11-13T02:05:51.969Z"}}]}}

{}

{"affected": [{"affectedData": [{"product": "UltraVNC", "vendor": "UltraVNC", "versions": [{"lessThanOrEqual": "1.8.2.6", "status": "affected", "version": "1.8.2.4", "versionType": "custom"}]}, {"product": "TightVNC", "vendor": "Glavsoft (TightVNC)", "versions": [{"lessThanOrEqual": "1.3.10", "status": "affected", "version": "1.3.10", "versionType": "custom"}]}], "source": "cret@cert.org"}], "cveTags": [], "descriptions": [{"lang": "en", "value": "Tight JPEG decoding in TightVNC and UltraVNC viewers contains a heap-based buffer overflow because an attacker-controlled framebuffer rectangle width is not validated against a fixed-size decoding buffer. A malicious VNC server can cause an out-of-bounds heap write when a user connects, resulting in application crash and potentially other memory-corruption impacts."}], "id": "CVE-2026-128321", "lastModified": "2026-11-13T02:18:56.493", "metrics": {}, "published": "2026-11-13T02:18:56.493", "references": [{"source": "cret@cert.org", "url": "https://github.com/ultravnc/ultravnc"}, {"source": "cret@cert.org", "url": "https://www.tightvnc.com/"}, {"source": "af854a3a-2127-422b-91ae-364da2661108", "url": "https://www.kb.cert.org/vuls/id/644655"}], "sourceIdentifier": "cret@cert.org", "vulnStatus": "Received"}

{}

{"created": "2026-11-14T21:45:21.821864+00:00", "updated": "2026-11-14T21:45:21.821872+00:00", "vendors": [], "weaknesses": ["CWE-119"]}