# CVE-2026-78660: Go net/http HTTP/2 transport malformed framing headers acceptance

Source: https://junglewise.ai/threats/cve-2026-78660-go-2026-6610-http-2-transport-accepts-malformed-framing-related  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-10-08. Updated: 2026-10-10  
License: CC BY 4.0 with a link back

CVE-2026-78660 · Severity: high · CVSS 7.5 · Published 2026-10-08

Go's HTTP/2 transport implementation accepts malformed headers related to framing, which could allow attackers to send specially crafted requests that violate the HTTP/2 specification. This may lead to protocol confusion or downstream service exploitation depending on how applications handle such requests.

Technologies: [go (Go)](https://junglewise.ai/threats/technologies/go). Vendors: [Go](https://junglewise.ai/threats/vendors/go).

## Quick answers

**Is CVE-2026-78660 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-78660 being exploited in the wild.

**How severe is CVE-2026-78660?** High severity, with a CVSS score of 7.5, published 8 October 2026.

**Which products and versions are affected?** go (Go) <UNKNOWN>.

**Is there a fix for CVE-2026-78660?** 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-2026-78660 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-78660?** Check whether you run go (Go) 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 Go's net/http package where the HTTP/2 transport fails to properly validate framing-related headers, allowing malformed headers to pass through without rejection. An attacker on the network can send crafted HTTP/2 frames with invalid headers to exploit this weakness. The impact depends on downstream services' behavior when receiving such malformed input.

## Affected products

- Go Go <UNKNOWN>

## Identifiers

- CVE-2026-78660
- GO-2026-6610

## Timeline

- 2026-10-08: disclosed

## References

- [https://go.dev/cl/835145](https://go.dev/cl/835145)
- [https://go.dev/cl/836385](https://go.dev/cl/836385)

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