CVE-2018-15501

Exp

In ng_pkt in transports/smart_pkt.c in libgit2 before 0.26.6 and 0.27.x before 0.27.4, a remote attacker can send a crafted smart-protocol "ng" packet that lacks a '\0' byte to trigger an out-of-bounds read that leads to DoS.

Published: 2018-08-17 Last update: 2026-06-16 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2018-15501 is rated High Exploit Risk (77.9/100): CVSS High severity, with medium exploitation likelihood (EPSS 4.34%). 1 public exploit reference(s) are indexed (Exploit-DB). EPSS rose +1.41% over the last day, indicating growing attacker interest. Public exploits are available—assess exposure, apply mitigations, and prioritize patching.

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

Public exploit references (Exploit-DB) for CVE-2018-15501

EDB-ID Source Kind Published Link
— nvd_ref exploit_tag Exploit-DB ↗

Exploit prediction scoring system (EPSS) score for CVE-2018-15501

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 2.92% 4.34% +1.41%
2 2026-05-27 1.62% 2.92% +1.30%
3 2026-04-05 — 1.62% —

Full EPSS history (15 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2018-15501

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]
5.0 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-2018-15501

OS Trackers for CVE-2018-15501

vendor priority summary link
alpine high CVE-2018-15501: 4 source package rows (libgit2, libgit2-1.0, libgit2-1.1, libgit2-1.5); 12 state rows across 9 repos (3.10-main, 3.11-main, 3.17-community, 3.18-community, 3.19-community, 3.20-community, 3.21-community, 3.22-community, edge-community); fixed 12, open 0. https://security.alpinelinux.org/vuln/CVE-2018-15501
debian low CVE-2018-15501 low priority: Debian including 1 source packages (libgit2), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2018-15501
redhat low — https://access.redhat.com/security/cve/CVE-2018-15501
suse medium CVE-2018-15501 severity moderate: SUSE including 11 source package names (libgit2, libgit2-24-0.24.1-7.6.1, …), 31 product×package rows across 17 product lines (SUSE Linux Enterprise Module for Development Tools 15, SUSE Linux Enterprise Module for Development Tools 15 SP1, … (17 product lines)): Fixed 25, Known Not Affected 6. https://www.suse.com/security/cve/CVE-2018-15501/
ubuntu medium CVE-2018-15501 medium priority: Ubuntu including 1 source packages (libgit2), 19 status rows across 19 suites (bionic, cosmic, disco, eoan, focal, groovy, hirsute, impish, jammy, kinetic, lunar, mantic, noble, oracular, plucky, questing, trusty, upstream, xenial): not-affected 15, needed 3, released 1. https://ubuntu.com/security/CVE-2018-15501

Affected software / configurations for CVE-2018-15501

Vendor Product Version Raw CPE
debian debian_linux 8.0 cpe:2.3:o:debian:debian_linux:8.0:*:*:*:*:*:*:*
debian debian_linux 9.0 cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:*
libgit2 libgit2 < 0.26.6 cpe:2.3:a:libgit2:libgit2:*:*:*:*:*:*:*:*
libgit2 libgit2 >= 0.27.0, < 0.27.4 cpe:2.3:a:libgit2:libgit2:*:*:*:*:*:*:*:*

References for CVE-2018-15501

URL Tags
https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=9406 Exploit Issue Tracking Patch Third Party Advisory
https://bugzilla.suse.com/show_bug.cgi?id=1104641 Issue Tracking Patch Third Party Advisory
https://github.com/libgit2/libgit2/commit/1f9a8510e1d2f20ed7334eeeddb92c4dd8e7c649 Patch Third Party Advisory
https://github.com/libgit2/libgit2/releases/tag/v0.26.6 Release Notes Third Party Advisory
https://github.com/libgit2/libgit2/releases/tag/v0.27.4 Release Notes Third Party Advisory
https://lists.debian.org/debian-lts-announce/2018/08/msg00024.html Mailing List Third Party Advisory
https://lists.debian.org/debian-lts-announce/2022/03/msg00031.html Mailing List Third Party Advisory
https://www.pro-linux.de/sicherheit/2/44650/denial-of-service-in-libgit2.html Third Party Advisory
cvelogic Threat Intelligence