CVE-2026-110673: CWE-674 Uncontrolled Recursion
Description
Cpanel::JSON::XS versions before 4.80 for Perl allow stack exhaustion via nested tagged values under allow_tags in decode_tag. With allow_tags, "(" starts a tagged value. Its tag and value are decoded recursively, and each can start another tagged value. Unlike arrays and objects, this nesting is not counted against max_depth. A run of "(" bytes exhausts the C stack and triggers an uncatchable segmentation fault regardless of max_depth.
Affected software
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Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The vulnerability arises because the decode_tag function in Cpanel::JSON::XS versions prior to 4.80 recursively decodes tagged values initiated by "(" characters under the allow_tags option. Unlike arrays and objects, the recursion depth for these tagged values is not limited by the max_depth parameter, allowing an attacker to craft deeply nested tagged values that exhaust the C stack. This results in an uncatchable segmentation fault, causing a denial of service.
Potential Impact
An attacker can cause a denial of service by triggering a segmentation fault through stack exhaustion. This fault is uncatchable, leading to potential application crashes or service interruptions when processing maliciously crafted JSON input with nested tagged values.
Mitigation Recommendations
Upgrade to Cpanel::JSON::XS version 4.80 or later where this issue is fixed. No other mitigation is indicated. Patch status is not explicitly stated but the affected versions are prior to 4.80, implying the fix is in 4.80.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- CPANSec
- Date Reserved
- 2026-10-14T13:22:59.046Z
- State
- PUBLISHED
Threat ID: 6ad662ba2cdf04f656803401
Added to database: 10/19/2026, 18:34:34 UTC
Last enriched: 10/19/2026, 18:49:10 UTC
Last updated: 10/19/2026, 22:27:04 UTC
Views: 8
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