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2 vulnerabilities by grunfink
CVE-2026-112021 (GCVE-0-2026-112021)
Vulnerability from nvd – Published: 2026-10-18 11:38 – Updated: 2026-10-19 16:05
VLAI
EPSS
VEX
Title
snac2 before 2.93 Heap-Based Buffer Overflow via JSON Parser _xs_json_load_lexer()
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. 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.
Severity
SSVC
Exploitation: poc
Automatable: yes
Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-10-19 16:04 UTC
CWE
- CWE-122 - Heap-based Buffer Overflow
Assigner
References
7 references
| URL | Tags |
|---|---|
| https://nullenvk.pl/posts/02-snac2-json | technical-description |
| https://gist.github.com/nullenvk/2bf288e2d34cb3d4… | exploit |
| https://codeberg.org/grunfink/snac2/src/tag/2.92/… | technical-description |
| https://codeberg.org/grunfink/snac2/commit/ec2c5c… | patch |
| https://codeberg.org/grunfink/snac2/releases/tag/2.93 | release-notes |
| https://codeberg.org/grunfink/snac2 | product |
| https://www.vulncheck.com/advisories/snac2-before… | third-party-advisory |
Date Public
2026-07-08 00:00
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CVE-2026-112021 (GCVE-0-2026-112021)
Vulnerability from cvelistv5 – Published: 2026-10-18 11:38 – Updated: 2026-10-19 16:05
VLAI
EPSS
VEX
Title
snac2 before 2.93 Heap-Based Buffer Overflow via JSON Parser _xs_json_load_lexer()
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. 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.
Severity
SSVC
Exploitation: poc
Automatable: yes
Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-10-19 16:04 UTC
CWE
- CWE-122 - Heap-based Buffer Overflow
Assigner
References
7 references
| URL | Tags |
|---|---|
| https://nullenvk.pl/posts/02-snac2-json | technical-description |
| https://gist.github.com/nullenvk/2bf288e2d34cb3d4… | exploit |
| https://codeberg.org/grunfink/snac2/src/tag/2.92/… | technical-description |
| https://codeberg.org/grunfink/snac2/commit/ec2c5c… | patch |
| https://codeberg.org/grunfink/snac2/releases/tag/2.93 | release-notes |
| https://codeberg.org/grunfink/snac2 | product |
| https://www.vulncheck.com/advisories/snac2-before… | third-party-advisory |
Date Public
2026-07-08 00:00
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