CVE-2025-29329
Published: 12 January 2026
Summary
CVE-2025-29329 is a critical-severity Classic Buffer Overflow (CWE-120) vulnerability in Sagemcom F\@St 3686 Firmware. Its CVSS base score is 9.8 (Critical).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked in the top 36.2% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.
The strongest mitigations our analysis identified are NIST 800-53 SI-10 (Information Input Validation) and SI-16 (Memory Protection).
Deeper analysis
CVE-2025-29329 is a buffer overflow vulnerability, classified under CWE-120, affecting the ippprint service that implements the Internet Printing Protocol in Sagemcom F@st 3686 routers running firmware version MAGYAR_4.121.0. Published on 2026-01-12, the flaw enables a remote attacker to execute arbitrary code by sending a crafted HTTP request to the vulnerable service.
The vulnerability carries a CVSS v3.1 base score of 9.8 (AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H), marking it as critical. Any unauthenticated remote attacker with network access to the device can exploit it with low complexity and no user interaction required, achieving high-impact compromise of confidentiality, integrity, and availability through arbitrary code execution.
Vendor advisories and additional details are available at http://fst.com and http://sagemcom.com, while a proof-of-concept exploit is hosted at https://github.com/SilverS3c/Sagemcom-fast-3686-ippprint.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2025-206276
Vulnerability details
Buffer Overflow in the ippprint (Internet Printing Protocol) service in Sagemcom F@st 3686 MAGYAR_4.121.0 allows remote attacker to execute arbitrary code by sending a crafted HTTP request.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
Buffer overflow in public-facing ippprint service (IPP over HTTP) enables unauthenticated remote arbitrary code execution, directly facilitating T1190: Exploit Public-Facing Application.
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Affected Assets
Mitigating Controls
Mitigating Controls (NIST 800-53 r5) AI
Directly remediates the buffer overflow flaw in the ippprint service by requiring timely patching of the vulnerable firmware.
Enforces validation of crafted HTTP requests to the ippprint service, preventing buffer overflows from malicious inputs.
Implements memory protections such as non-executable stacks and address space randomization to block arbitrary code execution from buffer overflows.