Uncontrolled Recursion in jackson-dataformats-text - #VU156696
Published: October 21, 2026
Vulnerability identifier: #VU156696
CSH Severity: Medium
CVSS v4: 8.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
CVE-ID: N/A
CWE-ID: CWE-674
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to cause a denial of service by crashing the YAML parsing thread.
The vulnerability exists due to uncontrolled recursion in YAMLAnchorReplayingParser.getEvent() when processing deeply nested YAML merge keys (<<). A remote attacker can submit a specially crafted YAML document to an application using YAMLAnchorReplayingFactory to exhaust the parsing thread's stack and trigger a StackOverflowError.
The standard YAMLFactory, which is the default factory, is not affected.
Affected software
jackson-dataformats-text
Remediation
Install security update from vendor's website.
jackson-dataformats-text - addressed in versions 2.18.12, 2.21.8, 2.22.4, 3.1.8, 3.2.4