Is CVE-2026-63382 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-63382 being exploited in the wild.

How severe is CVE-2026-63382?

Informational severity, published 20 August 2026.

Which products and versions are affected?

Libevent prior to 2.1.13 and 2.2.2-alpha.

Is there a fix for CVE-2026-63382?

A patch was published on 2026-08-20: Fixed in versions 2.1.13 and 2.2.2-alpha Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

How is CVE-2026-63382 attacked?

It is attacked over the network.

Am I affected by CVE-2026-63382?

Check whether you run Libevent 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.

CVE-2026-63382: Libevent HTTP request smuggling via inconsistent Transfer-Encoding parsing

CVE-2026-63382 · Severity: info · Published 2026-08-20

Libevent is a widely-used event notification library that provides HTTP parsing functionality. A flaw in how it parses HTTP chunked transfer encoding allows attackers to send maliciously-crafted requests that are interpreted differently by libevent than by upstream proxies, enabling request smuggling attacks. An attacker could exploit this to bypass authentication controls, poison cached content, or access restricted resources.

Technologies: Libevent. Vendors: Libevent.

Quick answers

Is CVE-2026-63382 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-63382 being exploited in the wild.
How severe is CVE-2026-63382?: Informational severity, published 20 August 2026.
Which products and versions are affected?: Libevent prior to 2.1.13 and 2.2.2-alpha.
Is there a fix for CVE-2026-63382?: A patch was published on 2026-08-20: Fixed in versions 2.1.13 and 2.2.2-alpha Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-63382 attacked?: It is attacked over the network.
Am I affected by CVE-2026-63382?: Check whether you run Libevent 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 libevent evhttp HTTP parser in http.c contains multiple inconsistencies in handling chunked transfer encoding: it accepts bare line feeds (LF) as chunk terminators instead of requiring strict CRLF per RFC 9112, uses evhttp_find_header() which only selects the first header when duplicates exist, lacks proper validation of comma-separated Transfer-Encoding values, and does not detect valid "chunked" encoding when it appears at the end of a comma-separated list. When libevent is deployed behind a reverse proxy or firewall that normalizes or frames HTTP differently, an unauthenticated remote attacker can craft a request with ambiguous framing that causes request desynchronization. This allows the attacker to smuggle a second request within the first, potentially bypassing access controls or authentication. The vulnerability affects versions prior to 2.1.13 and 2.2.2-alpha; patches are available in those releases.

Affected products

Libevent Libevent prior to 2.1.13 and 2.2.2-alpha

Timeline

2026-08-20: disclosed
2026-08-20: patched: Fixed in versions 2.1.13 and 2.2.2-alpha

References

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