Is CVE-2026-78659 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-78659 being exploited in the wild.

How severe is CVE-2026-78659?

High severity, with a CVSS score of 7.5, published 8 October 2026.

Is there a fix for CVE-2026-78659?

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-2026-78659 attacked?

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

Am I affected by CVE-2026-78659?

Check whether you run net/http (Go). 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-2026-78659: Go net/http HTTP/2 server memory exhaustion

CVE-2026-78659 · Severity: high · CVSS 7.5 · Published 2026-10-08

Go's HTTP/2 server implementation in the net/http library can be exhausted of memory when processing specially crafted Trailer headers. An attacker on the network can send malicious HTTP/2 requests to cause the server to consume excessive memory, potentially leading to denial of service by exhausting available resources and crashing the service.

Technologies: net/http (Go). Vendors: Go.

Quick answers

Is CVE-2026-78659 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-78659 being exploited in the wild.
How severe is CVE-2026-78659?: High severity, with a CVSS score of 7.5, published 8 October 2026.
Which products and versions are affected?: Go net/http.
Is there a fix for CVE-2026-78659?: 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-2026-78659 attacked?: It is attacked over the network, in a software library.
Am I affected by CVE-2026-78659?: Check whether you run net/http (Go). 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 HTTP/2 server in Go's net/http package fails to properly limit memory consumption when processing Trailer headers, allowing an attacker to craft requests that cause unbounded memory allocation. The vulnerability is triggered via network-based HTTP/2 requests without requiring authentication or user interaction. A fix has been made available through Go commits addressing memory management in HTTP/2 trailer handling.

Affected products

Go net/http

Identifiers

CVE-2026-78659
GO-2026-6603

Timeline

2026-10-08: disclosed

References

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