HIGH

CVE-2026-112021

CVSS v3

7.5

HIGH

EPSS Score

—

exploit probability

CISA KEV

known exploited

Exploitation

—

SSVC status

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Affected and fixed versions

Neither OSV.dev nor the vendor advisories we read list affected versions for CVE-2026-112021 yet.

Full record on NVD

Description

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.

Technical details

CVSS v3 Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Published: 2026-10-18
Last Modified: 2026-10-18

Frequently asked questions

What is CVE-2026-112021?

Is CVE-2026-112021 actively exploited?

Active exploitation of CVE-2026-112021 has not been confirmed.

What is the CVSS score for CVE-2026-112021?

CVE-2026-112021 has a CVSS v3 base score of 7.5 (HIGH severity), with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

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