CVE-2016-2338

Exp

An exploitable heap overflow vulnerability exists in the Psych::Emitter start_document function of Ruby. In Psych::Emitter start_document function heap buffer "head" allocation is made based on tags array length. Specially constructed object passed as element of tags array can increase this array size after mentioned allocation and cause heap overflow.

Published: 2022-09-29 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2016-2338 is rated High Exploit Risk (85.2/100): CVSS Critical severity, with high exploitation likelihood (EPSS 13.46%, 94th percentile). 1 public exploit reference(s) are indexed (Exploit-DB). 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-2016-2338

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

Exploit prediction scoring system (EPSS) score for CVE-2016-2338

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 2026-02-01 15.38% 13.46% -1.92%
2 2025-10-14 15.05% 15.38% +0.33%
3 2025-10-04 — 15.05% —

Full EPSS history (26 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2016-2338

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]

Weakness enumeration for CVE-2016-2338

OS Trackers for CVE-2016-2338

vendor priority summary link
redhat medium — https://access.redhat.com/security/cve/CVE-2016-2338
suse high CVE-2016-2338 severity important: SUSE including 10 source package names (libruby2_1-2_1, libruby2_5-2_5, …), 156 product×package rows across 36 product lines (SUSE CaaS Platform 4.0, SUSE Enterprise Storage 6, … (36 product lines)): Known Not Affected 156. https://www.suse.com/security/cve/CVE-2016-2338/
ubuntu medium CVE-2016-2338 medium priority: Ubuntu including 6 source packages (ruby-psych, ruby1.9.1, ruby2.0, ruby2.3, ruby2.5, ruby2.7), 30 status rows across 5 suites (bionic, eoan, trusty, upstream, xenial): DNE 19, needs-triage 6, not-affected 5. https://ubuntu.com/security/CVE-2016-2338

Affected software / configurations for CVE-2016-2338

Vendor Product Version Raw CPE
ruby-lang ruby 2.2.2 cpe:2.3:a:ruby-lang:ruby:2.2.2:*:*:*:*:*:*:*
ruby-lang ruby 2.3.0 cpe:2.3:a:ruby-lang:ruby:2.3.0:*:*:*:*:*:*:*
debian debian_linux 8.0 cpe:2.3:o:debian:debian_linux:8.0:*:*:*:*:*:*:*

References for CVE-2016-2338

cvelogic Threat Intelligence