# CVE-2026-80051: graphql-go GraphQL scalar type validation bypass

Source: https://junglewise.ai/threats/cve-2026-80051-graphql-go-graphql-scalar-type-validation-bypass  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-08-25. Updated: 2026-09-25  
License: CC BY 4.0 with a link back

CVE-2026-80051 · Severity: info · Published 2026-08-25

graphql-go is a GraphQL implementation for Go used to build GraphQL API servers. Versions through 0.8.1 fail to properly validate that variable values match their declared scalar types (String, ID, Boolean), allowing invalid inputs to be processed. In rare cases involving deeply nested values, this can trigger a stack overflow crash, causing temporary service unavailability.

## Quick answers

**Is CVE-2026-80051 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-80051 being exploited in the wild.

**How severe is CVE-2026-80051?** Informational severity, published 25 August 2026.

**Which products and versions are affected?** graphql-go graphql through 0.8.1.

**Is there a fix for CVE-2026-80051?** 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-2026-80051 attacked?** It is attacked over the network.

**Am I affected by CVE-2026-80051?** 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

The vulnerability exists in the scalar type coercion functions (coerceString and coerceBool) in scalars.go, which do not validate input type against the declared scalar type as required by the GraphQL specification. An attacker can send a GraphQL request with scalar variables whose runtime type does not match the declared type; the library accepts these invalid values instead of raising a type error. In specific scenarios involving deeply nested structures, this type mismatch can lead to unbounded recursion and a fatal stack overflow, resulting in a denial-of-service. The attack requires the ability to send arbitrary GraphQL queries to the application; typical JSON-based web requests are unlikely to trigger the stack overflow condition.

## Affected products

- graphql-go graphql through 0.8.1

## Timeline

- 2026-08-25: disclosed

## References

- [https://pkg.go.dev/](https://pkg.go.dev/)
- [https://github.com/graphql-go/graphql/blob/v0.8.1/scalars.go](https://github.com/graphql-go/graphql/blob/v0.8.1/scalars.go)