CVE-2025-11683 | YAML::Syck versions before 1.36 for Perl has missing Null-Terminators which causes Out-of-Bounds Read and potential Information Disclosure

YAML::Syck versions before 1.36 for Perl has missing null-terminators which causes out-of-bounds read and potential information disclosure Missing null terminators in token.c leads to but-of-bounds read which allows adjacent variable to be read The issue is seen with complex YAML files with a hash of all keys and empty values.  There is no indication that the issue leads to accessing memory outside that allocated to the module.

Published: 2025-10-16 Last update: 2026-03-09 Assigner: 9b29abf9-4ab0-4765-b253-1875cd9b441e Source: 9b29abf9-4ab0-4765-b253-1875cd9b441e
NVD Status：Analyzed，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2025-11683 is rated Low Risk (27.2/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.02%). Monitor for updates and reassess as exploit intelligence or EPSS changes.

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-2025-11683

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 2025-10-16 — 0.02% —

Full EPSS history (1 record total)

Common vulnerability scoring system (CVSS) metrics for CVE-2025-11683

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
6.5 3.1 MEDIUM
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N Click to expand
Attack vector (AV:A)
Attacker has to be nearby on the network—same office, same link, that vibe—not the whole wide internet.
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:N)
Data isn’t meaningfully altered or forged.
Availability (A:N)
Service keeps running; no real outage angle.
 2.8 3.6 134c704f-9b21-4f2e-91b3-4a467353bcc0

Weakness enumeration for CVE-2025-11683

OS Trackers for CVE-2025-11683

vendor priority summary link
debian not yet assigned CVE-2025-11683 not yet assigned priority: Debian including 1 source packages (libyaml-syck-perl), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2025-11683
redhat medium — https://access.redhat.com/security/cve/CVE-2025-11683
suse medium — https://www.suse.com/security/cve/CVE-2025-11683/
ubuntu medium CVE-2025-11683 medium priority: Ubuntu including 1 source packages (libyaml-syck-perl), 8 status rows across 8 suites (bionic, focal, jammy, noble, plucky, questing, upstream, xenial): released 8. https://ubuntu.com/security/CVE-2025-11683

Affected software / configurations for CVE-2025-11683

Vendor Product Version Raw CPE
toddr yaml::syck < 1.36 cpe:2.3:a:toddr:yaml\:\:syck:*:*:*:*:*:perl:*:*

References for CVE-2025-11683

cvelogic Threat Intelligence