Quick answers
- Is CVE-2026-8367 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-8367 being exploited in the wild.
- How severe is CVE-2026-8367?
- Medium severity, with a CVSS score of 4.8, published 13 May 2026.
- Which products and versions are affected?
- aria2 aria2c.
- Is there a fix for CVE-2026-8367?
- No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.
- How is CVE-2026-8367 attacked?
- It is attacked over the network, in a software library.
- Am I affected by CVE-2026-8367?
- Check whether you run Aria2. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.
Technical details
aria2c is vulnerable to improper certificate validation (CWE-295) because it does not strictly enforce the Extended Key Usage (EKU) field during the TLS handshake. Specifically, the application accepts certificates that lack the 'TLS Web Server Authentication' (serverAuth) purpose, such as those only marked for 'TLS Web Client Authentication' (clientAuth). An attacker who has compromised a private key and a certificate issued for a non-server purpose could perform a man-in-the-middle (MitM) attack or host a malicious server that aria2c would trust as a legitimate endpoint. This vulnerability requires the attacker to possess a validly signed certificate from a trusted CA, albeit one with incorrect EKU attributes.
Affected products
- aria2 aria2c
Timeline
- 2026-05-13: disclosed: Vulnerability disclosed by Tenable Research.
- 2026-05-13: advisory: NVD published CVE-2026-8367.