Quick answers
- Is CVE-2026-82726 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-82726 being exploited in the wild.
- How severe is CVE-2026-82726?
- Informational severity, published 31 August 2026.
- Which products and versions are affected?
- Ash-Project Ash Phoenix 2.1.26 to before 2.3.25.
- Is there a fix for CVE-2026-82726?
- 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-2026-82726 attacked?
- It is attacked over the network, in a software library.
- Am I affected by CVE-2026-82726?
- Check whether you run Ash-Project Ash Phoenix at an affected version. 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
The vulnerability exists in the AshPhoenix.Helpers.get_subdomain/2 function, which uses String.replace with an unanchored, global regular expression to strip the root domain from the Host header. The root_host parameter is interpolated raw into the regex pattern without escaping, allowing metacharacters like . to be interpreted as wildcards. This permits attackers to craft malicious Host headers (e.g., "foo.exampleXcom.attacker.net" to extract "foo.attacker.net" instead of "foo") to select arbitrary tenants. Additionally, the comparison is case-sensitive, allowing bypass of tenant allowlists with uppercase variants. The attack requires only a network-accessible application and no authentication. The fix matches the root host case-insensitively and only as an exact trailing suffix.
Affected products
- ash-project ash_phoenix 2.1.26 to before 2.3.25
Timeline
- 2026-08-31: published