Vulnerability · Published Sep 1, 2026 · Assigned by elastic
CVE-2026-78605Inconsistent Interpretation of HTTP Requests ('HTTP Request Smuggling') in Elasticsearch Leading to Information Disclosure
Medium 5.9
In plain English
A medium-severity security flaw in Elasticsearch from Elastic. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 27% of all known vulnerabilities).
Severity (CVSS 3.1)5.9Medium
Exploit odds (30 days)0.3%top 72.7% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known
Official description
Inconsistent Interpretation of HTTP Requests ('HTTP Request Smuggling') (CWE-444) in Elasticsearch can lead to information disclosure via HTTP Request Smuggling (CAPEC-33). Under specific proxy deployment configurations, a network attacker could obtain confidential responses intended for other authenticated users.
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| Elastic | Elasticsearch | 8.18.0 – through 8.19.199.0.0 – through 9.4.49.5.0 |
Weakness: CWE-444 · Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N