CVE-2019-16239

CRITICALNVD 9.89.8—

9.8

process_http_response in OpenConnect before 8.05 has a Buffer Overflow when a malicious server uses HTTP chunked encoding with crafted chunk sizes.

CVSS v3: 9.8
EG Score: 9.8(medium)
EPSS: 92.5%
KEV: Not listed

Published

September 17, 2019

Last Modified

November 21, 2024

References (22)

cve@mitrehttp://lists.infradead.org/pipermail/openconnect-devel/2019-September/005412.html
cve@mitrehttp://lists.opensuse.org/opensuse-security-announce/2019-10/msg00060.html
cve@mitrehttp://lists.opensuse.org/opensuse-security-announce/2019-10/msg00061.html
cve@mitrehttps://lists.debian.org/debian-lts-announce/2019/10/msg00003.html
cve@mitrehttps://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/FX56KYWC7X4ETV4P6HGJC7GZUEBITBBS/
cve@mitrehttps://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/HDMZGNBLZZKAGBI2PNXYWWKLD2LXKFH6/
cve@mitrehttps://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/WI7ZENFAWCHF2RU4NHPL2CU4WGZ4BNDJ/
cve@mitrehttps://seclists.org/bugtraq/2020/Jan/31
cve@mitrehttps://t2.fi/schedule/2019/
cve@mitrehttps://usn.ubuntu.com/4565-1/
cve@mitrehttps://www.debian.org/security/2020/dsa-4607
af854a3a-2127-422b-91ae-364da2661108http://lists.infradead.org/pipermail/openconnect-devel/2019-September/005412.html
af854a3a-2127-422b-91ae-364da2661108http://lists.opensuse.org/opensuse-security-announce/2019-10/msg00060.html
af854a3a-2127-422b-91ae-364da2661108http://lists.opensuse.org/opensuse-security-announce/2019-10/msg00061.html
af854a3a-2127-422b-91ae-364da2661108https://lists.debian.org/debian-lts-announce/2019/10/msg00003.html

Patch Availability(1)

Vendor / Ecosystem	Fixed in / Patch	Released	Source
ubuntu	openconnect (7.08-3ubuntu0.18.04.2) @ bionic	2026-05-27	ubuntu

Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

CWE-120Buffer Copy without Checking Size (Classic Buffer Overflow)

All Vendor Advisories

(1)

Every vendor that published an advisory referencing this CVE — pulled from our cve_vendor_advisories aggregation. Click any row for the vendor's original advisory page.

UbuntuUSN-4565-1MEDIUM
OpenConnect vulnerability

Data Freshness Timeline

(refreshed 6× in last 7d / 6× in last 30d)

Every time one of our enrichment pipelines (NVD, MITRE cvelistV5, EPSS, CISA KEV, GHSA, OSV, vendor advisories) ran against this CVE. Most recent first.

2026-05-27 14:29 UTCEG score recompute
2026-05-27 14:29 UTCVendor advisory
2026-05-27 14:29 UTCGHSA enrichment
2026-05-27 13:38 UTCepss_batch
2026-05-26 13:42 UTCepss_batch
2026-05-26 13:42 UTCepss_batch

Frequently asked(5)

What is CVE-2019-16239?

CVE-2019-16239 is a critical vulnerability published on September 17, 2019. processhttpresponse in OpenConnect before 8.05 has a Buffer Overflow when a malicious server uses HTTP chunked encoding with crafted chunk sizes.

When was CVE-2019-16239 disclosed?

CVE-2019-16239 was first published in the National Vulnerability Database on September 17, 2019, with the most recent update on November 21, 2024. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.

Is CVE-2019-16239 actively exploited?

CVE-2019-16239 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 92.5% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.

What is the CVSS score of CVE-2019-16239?

CVE-2019-16239 has a CVSS v3 base score of 9.8 (NVD).

How do I remediate CVE-2019-16239?

Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2019-16239, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

See which npm, PyPI, Go, and Maven packages are affected by CVE-2019-16239

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