CVE Catalog

CVE-2026-112021

HighCVSS 7.5
Published: Translated: NVD NIST

Summary

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. A single crafted application/activity+json POST to activitypub_post_handler() is parsed before signature checks, overflowing heap allocations and crashing the server.

Risk Assessment

An unauthenticated remote attacker can cause a server crash (denial of service) by sending a single crafted request, without needing authentication.

Recommendation

Update snac2 to version 2.93 or later, which fixes this vulnerability.

Related vulnerabilities

Original NVD description (English source)

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.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS