CVE-2017-11465

The parser_yyerror function in the UTF-8 parser in Ruby 2.4.1 allows attackers to cause a denial of service (invalid write or read) or possibly have unspecified other impact via a crafted Ruby script, related to the parser_tokadd_utf8 function in parse.y. NOTE: this might have security relevance as a bypass of a $SAFE protection mechanism.

Published: 2017-07-19 Last update: 2026-06-16 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2017-11465 is rated High Risk (66.4/100): CVSS Critical severity, with medium exploitation likelihood (EPSS 1.68%). Core evidence: EPSS rose +1.34% over the last day, indicating growing attacker interest. Mandatory action: 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-2017-11465

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 0.34% 1.68% +1.34%
2 2025-12-28 0.39% 0.34% -0.05%
3 2025-12-27 0.39%

Full EPSS history (15 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2017-11465

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
9.8 3.0 CRITICAL
CVSS:3.0/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]
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-2017-11465

OS Trackers for CVE-2017-11465

vendor priority summary link
redhat low https://access.redhat.com/security/cve/CVE-2017-11465
ubuntu medium CVE-2017-11465 medium priority: Ubuntu including 3 source packages (ruby1.9.1, ruby2.0, ruby2.3), 15 status rows across 5 suites (trusty, upstream, xenial, yakkety, zesty): DNE 9, not-affected 6. https://ubuntu.com/security/CVE-2017-11465

Affected software / configurations for CVE-2017-11465

Vendor Product Version Raw CPE
ruby-lang ruby 2.4.1 cpe:2.3:a:ruby-lang:ruby:2.4.1:*:*:*:*:*:*:*

References for CVE-2017-11465

URL Tags
https://bugs.ruby-lang.org/issues/13742 Issue Tracking Patch Vendor Advisory
https://bugs.ruby-lang.org/projects/ruby-trunk/repository/revisions/59344 Issue Tracking Patch Vendor Advisory
cvelogic Threat Intelligence