CVE-2018-16890

libcurl versions from 7.36.0 to before 7.64.0 is vulnerable to a heap buffer out-of-bounds read. The function handling incoming NTLM type-2 messages (`lib/vauth/ntlm.c:ntlm_decode_type2_target`) does not validate incoming data correctly and is subject to an integer overflow vulnerability. Using that overflow, a malicious or broken NTLM server could trick libcurl to accept a bad length + offset combination that would lead to a buffer read out-of-bounds.

Published: 2019-02-06 Last update: 2026-06-16 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2018-16890 is rated High Risk (66.2/100): CVSS High severity, with high exploitation likelihood (EPSS 5.35%, 92th percentile). EPSS ranks this CVE among the most likely to be exploited in the near term. EPSS rose +4.15% over the last day, indicating growing attacker interest. High exploitation likelihood—assess exposure and prioritize remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2018-16890

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 1.20% 5.35% +4.15%
2 2026-05-31 1.15% 1.20% +0.06%
3 2026-05-29 — 1.15% —

Full EPSS history (31 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2018-16890

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.5 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.9 3.6 [email protected]
5.4 3.0 MEDIUM
CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:L Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:R)
A real person has to do something—click, install, enable—otherwise it doesn’t land.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:L)
Some sensitive info could get out, but not a total data dump.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:L)
Might cause slowdowns, glitches, or partial disruption—not a full brick.
 2.8 2.5 [email protected]
5.0 2.0 MEDIUM
AV:N/AC:L/Au:N/C:N/I:N/A:P Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:N)
No confidentiality impact.
Integrity impact (I:N)
No integrity impact.
Availability impact (A:P)
Partial availability impact.
 10.0 2.9 [email protected]

Weakness enumeration for CVE-2018-16890

OS Trackers for CVE-2018-16890

vendor priority summary link
alpine high CVE-2018-16890: 1 source package rows (curl); 10 state rows across 10 repos (3.10-main, 3.11-main, 3.12-main, 3.17-main, 3.18-main, 3.19-main, 3.20-main, 3.21-main, 3.22-main, edge-main); fixed 10, open 0. https://security.alpinelinux.org/vuln/CVE-2018-16890
debian not yet assigned CVE-2018-16890 not yet assigned priority: Debian including 1 source packages (curl), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2018-16890
redhat medium — https://access.redhat.com/security/cve/CVE-2018-16890
suse medium CVE-2018-16890 severity moderate: SUSE including 359 source package names (0.1.0:libcurl4-7.60.0-3.17.1, 0.1.75:libcurl4-7.60.0-3.17.1, …), 439 product×package rows across 98 product lines (Container caasp/v4/389-ds, Container caasp/v4/busybox, … (98 product lines)): Fixed 267, Known Affected 157, Known Not Affected 15. https://www.suse.com/security/cve/CVE-2018-16890/
ubuntu medium CVE-2018-16890 medium priority: Ubuntu including 1 source packages (curl), 5 status rows across 5 suites (bionic, cosmic, trusty, upstream, xenial): released 4, not-affected 1. https://ubuntu.com/security/CVE-2018-16890

Affected software / configurations for CVE-2018-16890

Vendor Product Version Raw CPE
haxx libcurl >= 7.36.0, < 7.64.0 cpe:2.3:a:haxx:libcurl:*:*:*:*:*:*:*:*
canonical ubuntu_linux 14.04 cpe:2.3:o:canonical:ubuntu_linux:14.04:*:*:*:lts:*:*:*
canonical ubuntu_linux 16.04 cpe:2.3:o:canonical:ubuntu_linux:16.04:*:*:*:lts:*:*:*
canonical ubuntu_linux 18.04 cpe:2.3:o:canonical:ubuntu_linux:18.04:*:*:*:lts:*:*:*
canonical ubuntu_linux 18.10 cpe:2.3:o:canonical:ubuntu_linux:18.10:*:*:*:*:*:*:*
debian debian_linux 9.0 cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:*
netapp clustered_data_ontap — cpe:2.3:o:netapp:clustered_data_ontap:*:*:*:*:*:*:*:*
siemens sinema_remote_connect_client <= 2.0 cpe:2.3:a:siemens:sinema_remote_connect_client:*:*:*:*:*:*:*:*
oracle communications_operations_monitor 3.4 cpe:2.3:a:oracle:communications_operations_monitor:3.4:*:*:*:*:*:*:*
oracle communications_operations_monitor 4.0 cpe:2.3:a:oracle:communications_operations_monitor:4.0:*:*:*:*:*:*:*
oracle http_server 12.2.1.3.0 cpe:2.3:a:oracle:http_server:12.2.1.3.0:*:*:*:*:*:*:*
oracle secure_global_desktop 5.4 cpe:2.3:a:oracle:secure_global_desktop:5.4:*:*:*:*:*:*:*
redhat enterprise_linux 8.0 cpe:2.3:o:redhat:enterprise_linux:8.0:*:*:*:*:*:*:*
f5 big-ip_access_policy_manager >= 13.1.0, <= 13.1.3 cpe:2.3:a:f5:big-ip_access_policy_manager:*:*:*:*:*:*:*:*
f5 big-ip_access_policy_manager >= 14.0.0, <= 14.1.2 cpe:2.3:a:f5:big-ip_access_policy_manager:*:*:*:*:*:*:*:*
f5 big-ip_access_policy_manager >= 15.0.0, <= 15.0.1 cpe:2.3:a:f5:big-ip_access_policy_manager:*:*:*:*:*:*:*:*

References for CVE-2018-16890

URL Tags
http://www.securityfocus.com/bid/106947 Third Party Advisory VDB Entry
https://access.redhat.com/errata/RHSA-2019:3701 Third Party Advisory
https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2018-16890 Issue Tracking Mitigation Patch Third Party Advisory
https://cert-portal.siemens.com/productcert/pdf/ssa-436177.pdf Third Party Advisory
https://curl.haxx.se/docs/CVE-2018-16890.html Patch Vendor Advisory
https://lists.apache.org/thread.html/8338a0f605bdbb3a6098bb76f666a95fc2b2f53f37fa1ecc89f1146f%40%3Cdevnull.infra.apache.org%3E
https://security.netapp.com/advisory/ntap-20190315-0001/ Patch Third Party Advisory
https://support.f5.com/csp/article/K03314397?utm_source=f5support&amp%3Butm_medium=RSS
https://usn.ubuntu.com/3882-1/ Third Party Advisory
https://www.debian.org/security/2019/dsa-4386 Third Party Advisory
https://www.oracle.com/technetwork/security-advisory/cpuapr2019-5072813.html Patch Third Party Advisory
https://www.oracle.com/technetwork/security-advisory/cpujul2019-5072835.html Patch Third Party Advisory
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