grunfink snac2 up to 2.92 _xs_json_load_lexer buffer overflow

Summaryinfo

A vulnerability was found in grunfink snac2 up to 2.92. It has been rated as critical. Affected by this vulnerability is the function _xs_json_load_lexer. This manipulation causes buffer overflow. The identification of this vulnerability is CVE-2026-112021. It is possible to initiate the attack remotely. There is no exploit available. Upgrading the affected component is advised.

Detailsinfo

A vulnerability was found in grunfink snac2 up to 2.92. It has been declared as critical. Affected by this vulnerability is the function _xs_json_load_lexer. The manipulation with an unknown input leads to a buffer overflow vulnerability. The CWE definition for the vulnerability is CWE-120. The product copies an input buffer to an output buffer without verifying that the size of the input buffer is less than the size of the output buffer, leading to a buffer overflow. As an impact it is known to affect confidentiality, integrity, and availability. The summary by CVE is:

snac2 before 2.93 contains a heap-based buffer overflow vulnerability in _xs_json_load_lexer() that allows unauthenticated remote attackers to corrupt heap memory by sending JSON strings containing a \u0000 escape. Attackers can send a single crafted application/activity+json POST to activitypub_post_handler(), which parses it before signature checks, overflowing heap allocations and crashing the server.

The advisory is shared at nullenvk.pl. This vulnerability is known as CVE-2026-112021 since 10/18/2026. The exploitation appears to be easy. The attack can be launched remotely. The exploitation doesn't need any form of authentication. Technical details are known, but no exploit is available.

Upgrading to version 2.93 eliminates this vulnerability.

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Productinfo

Vendor

• grunfink

Name

• snac2

Version

• 2.0
• 2.1
• 2.2
• 2.3
• 2.4
• 2.5
• 2.6
• 2.7
• 2.8
• 2.9
• 2.10
• 2.11
• 2.12
• 2.13
• 2.14
• 2.15
• 2.16
• 2.17
• 2.18
• 2.19
• 2.20
• 2.21
• 2.22
• 2.23
• 2.24
• 2.25
• 2.26
• 2.27
• 2.28
• 2.29
• 2.30
• 2.31
• 2.32
• 2.33
• 2.34
• 2.35
• 2.36
• 2.37
• 2.38
• 2.39
• 2.40
• 2.41
• 2.42
• 2.43
• 2.44
• 2.45
• 2.46
• 2.47
• 2.48
• 2.49
• 2.50
• 2.51
• 2.52
• 2.53
• 2.54
• 2.55
• 2.56
• 2.57
• 2.58
• 2.59
• 2.60
• 2.61
• 2.62
• 2.63
• 2.64
• 2.65
• 2.66
• 2.67
• 2.68
• 2.69
• 2.70
• 2.71
• 2.72
• 2.73
• 2.74
• 2.75
• 2.76
• 2.77
• 2.78
• 2.79
• 2.80
• 2.81
• 2.82
• 2.83
• 2.84
• 2.85
• 2.86
• 2.87
• 2.88
• 2.89
• 2.90
• 2.91
• 2.92

CPE 2.3info

• 🔒
• 🔒
• 🔒

CPE 2.2info

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Entryinfo

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

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