cPanel Cpanel::JSON::XS up to 4.79 JSON Decoder decode_tag allow_tags stack-based overflow

Summaryinfo

A vulnerability labeled as problematic has been found in cPanel Cpanel::JSON::XS up to 4.79. This vulnerability affects the function decode_tag of the component JSON Decoder. The manipulation of the argument allow_tags results in stack-based overflow. This vulnerability is reported as CVE-2026-110673. The attack can be launched remotely. No exploit exists. The affected component should be upgraded.

Detailsinfo

A vulnerability was found in cPanel Cpanel::JSON::XS up to 4.79. It has been classified as problematic. Affected is the function decode_tag of the component JSON Decoder. The manipulation of the argument allow_tags with an unknown input leads to a stack-based overflow vulnerability. CWE is classifying the issue as CWE-121. A stack-based buffer overflow condition is a condition where the buffer being overwritten is allocated on the stack (i.e., is a local variable or, rarely, a parameter to a function). This is going to have an impact on availability. CVE summarizes:

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.

The advisory is available at github.com. This vulnerability is traded as CVE-2026-110673 since 10/14/2026. The exploitability is told to be easy. It is possible to launch the attack remotely. The exploitation doesn't require any form of authentication. Technical details are known, but there is no available exploit.

Upgrading to version 4.80 eliminates this vulnerability. Applying the patch 995eb484a9351753e2a8ec3317918b5b4a4e086a is able to eliminate this problem. The best possible mitigation is suggested to be upgrading to the latest version.

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Productinfo

Type

• Hosting Control Software

Vendor

• cPanel

Name

• Cpanel::JSON::XS

Version

• 4.0
• 4.1
• 4.2
• 4.3
• 4.4
• 4.5
• 4.6
• 4.7
• 4.8
• 4.9
• 4.10
• 4.11
• 4.12
• 4.13
• 4.14
• 4.15
• 4.16
• 4.17
• 4.18
• 4.19
• 4.20
• 4.21
• 4.22
• 4.23
• 4.24
• 4.25
• 4.26
• 4.27
• 4.28
• 4.29
• 4.30
• 4.31
• 4.32
• 4.33
• 4.34
• 4.35
• 4.36
• 4.37
• 4.38
• 4.39
• 4.40
• 4.41
• 4.42
• 4.43
• 4.44
• 4.45
• 4.46
• 4.47
• 4.48
• 4.49
• 4.50
• 4.51
• 4.52
• 4.53
• 4.54
• 4.55
• 4.56
• 4.57
• 4.58
• 4.59
• 4.60
• 4.61
• 4.62
• 4.63
• 4.64
• 4.65
• 4.66
• 4.67
• 4.68
• 4.69
• 4.70
• 4.71
• 4.72
• 4.73
• 4.74
• 4.75
• 4.76
• 4.77
• 4.78
• 4.79

License

• commercial

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CPE 2.2info

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