CVE-2026-5244
Description
A vulnerability has been found in Cesanta Mongoose up to 7.20. This affects the function mg_tls_recv_cert of the file mongoose.c of the component TLS 1.3 Handler. Such manipulation of the argument pubkey leads to heap-based buffer overflow. The attack may be launched remotely. The exploit has been disclosed to the public and may be used. Upgrading to version 7.21 mitigates this issue. The name of the patch is 0d882f1b43ff2308b7486a56a9d60cd6dba8a3f1. It is advisable to upgrade the affected component. The vendor was contacted early, responded in a very professional manner and quickly released a fixed version of the affected product.
Predictions
Heuristic predictions, AS-IS, for prioritization only.
Mitigations
Vendor advisory: debian — https://security-tracker.debian.org/tracker/CVE-2026-5244
Vendor advisory: cna@vuldb.com — https://github.com/cesanta/mongoose/releases/tag/7.21
Vendor advisory: cna@vuldb.com — https://github.com/cesanta/mongoose/commit/0d882f1b43ff2308b7486a56a9d60cd6dba8a3f1
OS impact
| OS | Version | Status | Fixed in |
|---|---|---|---|
| debian | forky | fixed | 0 |
| debian | sid | fixed | 0 |
| debian | bookworm | affected | |
| debian | bullseye | affected | |
| debian | trixie | affected | |
Application impact
| Vendor | Product | Versions | Fixed |
|---|---|---|---|
| cesanta | mongoose | {"startIncluding":"7.0","endExcluding":"7.21"} | 7.21 |
References
- https://github.com/cesanta/mongoose/
- https://github.com/cesanta/mongoose/commit/0d882f1b43ff2308b7486a56a9d60cd6dba8a3f1
- https://github.com/cesanta/mongoose/releases/tag/7.21
- https://vuldb.com/submit/770063
- https://vuldb.com/vuln/354825
- https://vuldb.com/vuln/354825/cti
- https://security-tracker.debian.org/tracker/CVE-2026-5244
CWEs
CWE-119 CWE-122
Verify integrity in audit chain (admin only). AS-IS.