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CVE-2026-112021 is a heap-based buffer overflow in the _xs_json_load_lexer() JSON parsing function in snac2 versions before 2.93. An unauthenticated remote attacker can trigger the vulnerability with a single crafted application/activity+json POST containing a JSON string with a \u0000 escape. The activitypub_post_handler() function parses the request before verifying its signature, allowing attacker-controlled input to overflow heap allocations, corrupt heap memory, and crash the server.
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A heap-based buffer overflow in snac2 versions before 2.93 permits unauthenticated remote denial of service. A single crafted application/activity+json POST to activitypub_post_handler() triggers JSON parsing before signature verification, corrupting heap memory and crashing the server. The reference rates the vulnerability High, with CVSS v3 7.5 and CVSS v4 8.7. The Nessus plugin identifies affected packages using vendor-reported package information rather than exploit validation. It reports no vendor-supplied patch or known solution for the covered packages.
A heap-based buffer overflow affects snac2 versions before 2.93. An unauthenticated remote attacker can send a single crafted application/activity+json POST to activitypub_post_handler(), triggering vulnerable JSON parsing before signature verification. This can corrupt heap memory and crash the server, causing denial of service.
A heap-based buffer overflow in the snac2 JSON parser affects versions before 2.93. An unauthenticated remote attacker can send a crafted application/activity+json POST to activitypub_post_handler(), triggering heap corruption and a server crash because parsing occurs before signature verification. The content reports CVSS scores of 7.5 under version 3.1 and 8.7 under version 4.0. Upgrading to snac2 2.93 or later fixes the flaw; restricting access to affected services is also recommended.
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Cross-references every affected SKU, including bundled OEM variants.
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