CVE-2019-19334

In all versions of libyang before 1.0-r5, a stack-based buffer overflow was discovered in the way libyang parses YANG files with a leaf of type "identityref". An application that uses libyang to parse untrusted YANG files may be vulnerable to this flaw, which would allow an attacker to cause a denial of service or possibly gain code execution.

Published: 2019-12-06 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2019-19334 is rated High Risk (74/100): CVSS Critical severity, with medium exploitation likelihood (EPSS 3.98%). EPSS rose +3.63% 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-2019-19334

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 0.35% 3.98% +3.63%
2 2026-05-09 0.66% 0.35% -0.31%
3 2026-04-22 — 0.66% —

Full EPSS history (19 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2019-19334

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
9.8 3.1 CRITICAL
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/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:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.9 5.9 [email protected]
8.1 3.0 HIGH
CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/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:H)
Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
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:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 2.2 5.9 [email protected]
7.5 2.0 HIGH
AV:N/AC:L/Au:N/C:P/I:P/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:P)
Partial confidentiality impact.
Integrity impact (I:P)
Partial integrity impact.
Availability impact (A:P)
Partial availability impact.
 10.0 6.4 [email protected]

Weakness enumeration for CVE-2019-19334

OS Trackers for CVE-2019-19334

vendor priority summary link
debian not yet assigned CVE-2019-19334 not yet assigned priority: Debian including 1 source packages (libyang), 4 status rows across 4 suites (bullseye, forky, sid, trixie): resolved 4. https://security-tracker.debian.org/tracker/CVE-2019-19334
redhat high — https://access.redhat.com/security/cve/CVE-2019-19334
ubuntu medium CVE-2019-19334 medium priority: Ubuntu including 1 source packages (libyang), 7 status rows across 7 suites (bionic, disco, eoan, focal, trusty, upstream, xenial): DNE 3, ignored 2, not-affected 1, released 1. https://ubuntu.com/security/CVE-2019-19334

Affected software / configurations for CVE-2019-19334

Vendor Product Version Raw CPE
cesnet libyang 0.11 cpe:2.3:a:cesnet:libyang:0.11:r1:*:*:*:*:*:*
cesnet libyang 0.11 cpe:2.3:a:cesnet:libyang:0.11:r2:*:*:*:*:*:*
cesnet libyang 0.12 cpe:2.3:a:cesnet:libyang:0.12:r1:*:*:*:*:*:*
cesnet libyang 0.12 cpe:2.3:a:cesnet:libyang:0.12:r2:*:*:*:*:*:*
cesnet libyang 0.13 cpe:2.3:a:cesnet:libyang:0.13:r1:*:*:*:*:*:*
cesnet libyang 0.13 cpe:2.3:a:cesnet:libyang:0.13:r2:*:*:*:*:*:*
cesnet libyang 0.14 cpe:2.3:a:cesnet:libyang:0.14:r1:*:*:*:*:*:*
cesnet libyang 0.15 cpe:2.3:a:cesnet:libyang:0.15:r1:*:*:*:*:*:*
cesnet libyang 0.16 cpe:2.3:a:cesnet:libyang:0.16:r1:*:*:*:*:*:*
cesnet libyang 0.16 cpe:2.3:a:cesnet:libyang:0.16:r2:*:*:*:*:*:*
cesnet libyang 0.16 cpe:2.3:a:cesnet:libyang:0.16:r3:*:*:*:*:*:*
cesnet libyang 1.0 cpe:2.3:a:cesnet:libyang:1.0:r1:*:*:*:*:*:*
cesnet libyang 1.0 cpe:2.3:a:cesnet:libyang:1.0:r2:*:*:*:*:*:*
cesnet libyang 1.0 cpe:2.3:a:cesnet:libyang:1.0:r3:*:*:*:*:*:*
cesnet libyang 1.0 cpe:2.3:a:cesnet:libyang:1.0:r4:*:*:*:*:*:*
redhat enterprise_linux 8.0 cpe:2.3:o:redhat:enterprise_linux:8.0:*:*:*:*:*:*:*
fedoraproject fedora 31 cpe:2.3:o:fedoraproject:fedora:31:*:*:*:*:*:*:*

References for CVE-2019-19334

cvelogic Threat Intelligence