CVE-2026-24904
TrustTunnel has `client_random_prefix` rule bypass via fragmented or partial TLS ClientHello
Description
TrustTunnel is an open-source VPN protocol with a rule bypass issue in versions prior to 0.9.115. In `tls_listener.rs`, `TlsListener::listen()` peeks 1024 bytes and calls `extract_client_random(...)`. If `parse_tls_plaintext` fails (for example, a fragmented/partial ClientHello split across TCP writes), `extract_client_random` returns `None`. In `rules.rs`, `RulesEngine::evaluate` only evaluates `client_random_prefix` when `client_random` is `Some(...)`. As a result, when extraction fails (`client_random == None`), any rule that relies on `client_random_prefix` matching is skipped and evaluation falls through to later rules. As an important semantics note: `client_random_prefix` is a match condition only. It does not mean "block non-matching prefixes" by itself. A rule with `client_random_prefix = ...` triggers its `action` only when the prefix matches (and the field is available to evaluate). Non-matches (or `None`) simply do not match that rule and continue to fall through. The vulnerability is fixed in version 0.9.115.
INFO
Published Date :
Jan. 29, 2026, 10:15 p.m.
Last Modified :
Feb. 20, 2026, 8:58 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | MEDIUM | [email protected] | ||||
| CVSS 3.1 | MEDIUM | MITRE-CVE |
Solution
- Update TrustTunnel to version 0.9.115.
- Verify rule evaluation logic after update.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-24904.
| URL | Resource |
|---|---|
| https://github.com/TrustTunnel/TrustTunnel/commit/aa5060145506952b9431b0ed3edb52bb6c08d9a6 | Patch |
| https://github.com/TrustTunnel/TrustTunnel/security/advisories/GHSA-fqh7-r5gf-3r87 | Exploit Vendor Advisory Patch |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-24904 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-24904
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-24904 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-24904 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
Initial Analysis by [email protected]
Feb. 20, 2026
Action Type Old Value New Value Added CPE Configuration OR *cpe:2.3:a:adguard:trusttunnel:*:*:*:*:*:*:*:* versions up to (excluding) 0.9.115 Added Reference Type GitHub, Inc.: https://github.com/TrustTunnel/TrustTunnel/commit/aa5060145506952b9431b0ed3edb52bb6c08d9a6 Types: Patch Added Reference Type GitHub, Inc.: https://github.com/TrustTunnel/TrustTunnel/security/advisories/GHSA-fqh7-r5gf-3r87 Types: Exploit, Patch, Vendor Advisory -
New CVE Received by [email protected]
Jan. 29, 2026
Action Type Old Value New Value Added Description TrustTunnel is an open-source VPN protocol with a rule bypass issue in versions prior to 0.9.115. In `tls_listener.rs`, `TlsListener::listen()` peeks 1024 bytes and calls `extract_client_random(...)`. If `parse_tls_plaintext` fails (for example, a fragmented/partial ClientHello split across TCP writes), `extract_client_random` returns `None`. In `rules.rs`, `RulesEngine::evaluate` only evaluates `client_random_prefix` when `client_random` is `Some(...)`. As a result, when extraction fails (`client_random == None`), any rule that relies on `client_random_prefix` matching is skipped and evaluation falls through to later rules. As an important semantics note: `client_random_prefix` is a match condition only. It does not mean "block non-matching prefixes" by itself. A rule with `client_random_prefix = ...` triggers its `action` only when the prefix matches (and the field is available to evaluate). Non-matches (or `None`) simply do not match that rule and continue to fall through. The vulnerability is fixed in version 0.9.115. Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N Added CWE CWE-284 Added Reference https://github.com/TrustTunnel/TrustTunnel/commit/aa5060145506952b9431b0ed3edb52bb6c08d9a6 Added Reference https://github.com/TrustTunnel/TrustTunnel/security/advisories/GHSA-fqh7-r5gf-3r87