Heap-based Buffer Overflow Affecting snac2 package, versions *


Severity

Recommended
0.0
high
0
10

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Threat Intelligence

EPSS
0.67% (52nd percentile)

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  • Snyk IDSNYK-ECHOLATEST-SNAC2-21246243
  • published19 Oct 2026
  • disclosed18 Oct 2026

Introduced: 18 Oct 2026

NewCVE-2026-112021  (opens in a new tab)
CWE-122  (opens in a new tab)

How to fix?

There is no fixed version for Echo:latest snac2.

NVD Description

Note: Versions mentioned in the description apply only to the upstream snac2 package and not the snac2 package as distributed by Echo. See How to fix? for Echo:latest relevant fixed versions and status.

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.

CVSS Base Scores

version 3.1