Is CVE-2026-75484 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-75484 being exploited in the wild.

How severe is CVE-2026-75484?

Informational severity, with a CVSS score of 0, published 20 August 2026.

Which products and versions are affected?

mtrudel bandit 1.4.0 before 1.12.5.

Is there a fix for CVE-2026-75484?

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-2026-75484 attacked?

It is attacked over the network, in a software library.

Am I affected by CVE-2026-75484?

Check whether anything you run is named in the advisory. 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-2026-75484: mtrudel bandit CRLF injection in HTTP/2 headers

CVE-2026-75484 · Severity: info · CVSS 0 · Published 2026-08-20

Bandit is an HTTP server library used to build web applications in Elixir. An attacker can inject carriage return, line feed, or null characters into HTTP/2 request headers without authentication. While Bandit itself doesn't directly exploit these injected characters, downstream applications that log or forward these headers verbatim could be vulnerable to log injection or request smuggling attacks.

Quick answers

Is CVE-2026-75484 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-75484 being exploited in the wild.
How severe is CVE-2026-75484?: Informational severity, with a CVSS score of 0, published 20 August 2026.
Which products and versions are affected?: mtrudel bandit 1.4.0 before 1.12.5.
Is there a fix for CVE-2026-75484?: 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-2026-75484 attacked?: It is attacked over the network, in a software library.
Am I affected by CVE-2026-75484?: Check whether anything you run is named in the advisory. 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

This is a CRLF injection vulnerability in the HTTP/2 header parsing logic of Bandit. The root cause is that Bandit.HTTP2.Stream.read_headers/1 validates pseudo-header placement, uniqueness, casing, and certain header values, but does not validate that field values are free of carriage return (\r), line feed (\n), or null (\0) characters. Because HPACK (HTTP/2 header compression) can carry arbitrary octets, malicious characters pass through unchanged into conn.req_headers. The HTTP/1 code path already rejects these characters, but HTTP/2 did not. The attack is unauthenticated and network-reachable. An additional related issue is that duplicate :authority pseudo-headers are accepted instead of rejected. The impact depends on how the application consumes header values; direct log injection or upstream request smuggling are possible if headers are concatenated unsanitized.

Affected products

mtrudel bandit 1.4.0 before 1.12.5

Timeline

2026-08-20: disclosed

References

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