# CVE-2026-52880: Klever-Go: REST API slow-header connection exhaustion via Gin Engine.Run

> Unauthenticated attackers can exhaust server file descriptors via slow-header connections, causing denial of service for the REST API.

- **Severity:** High 7.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 7 Aug 2026
- **Updated:** 11 Aug 2026
- **Also known as:** GHSA-w4c6-7r69-w7j9, GO-2026-5686

## What is CVE-2026-52880?

CVE-2026-52880 is a high-severity denial of service vulnerability in klever-io klever-go, published on 7 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Klever-Go is the Go implementation of the Klever blockchain protocol. Versions from 1.7.14 through 1.7.17 are vulnerable to a remotely triggerable denial of service. Both REST APIs are started with the Gin Engine.Run convenience method, which serves requests through Go's default HTTP server with no ReadHeaderTimeout, ReadTimeout, or MaxHeaderBytes configured. As a result, incoming connections that never complete their request headers are held open indefinitely. When a REST listener is reachable beyond localhost through the documented all-interface bind or a Docker port-publish deployment, a single unauthenticated client can open many slow-header connections and hold them open until server file descriptors are exhausted, preventing the API from accepting new connections. This renders the REST API unavailable to legitimate clients. This issue is fixed in version 1.7.18.

Weakness: CWE-770 (Allocation of Resources Without Limits or Throttling), CWE-400 (Uncontrolled Resource Consumption)

## Which versions are affected by CVE-2026-52880?

3 open source packages ship an affected version, including github.com/klever-io/klever-go.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `github.com/klever-io/klever-go` | Go | From 1.7.14 | 1.7.18 |
| `github.com/klever-io/klever-go` | Go | From 1.7.14 | 1.7.18 |
| `github.com/klever-io/klever-go` | Go | From 1.7.14 | 1.7.18 |

## How do I fix CVE-2026-52880?

Upgrade github.com/klever-io/klever-go to 1.7.18 or later.

## Is CVE-2026-52880 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-52880 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-52880 and fix it if it is affected.

What it is: CVE-2026-52880 is a high-severity denial of service vulnerability in klever-io klever-go, published on 7 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-52880 exists.

Affected packages and fixed versions:
- github.com/klever-io/klever-go (Go): affected from 1.7.14; fixed in 1.7.18
- github.com/klever-io/klever-go (Go): affected from 1.7.14; fixed in 1.7.18
- github.com/klever-io/klever-go (Go): affected from 1.7.14; fixed in 1.7.18

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-52880/ (Markdown: https://insights.sbomify.com/CVE-2026-52880/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-52880
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-52880
- OSV: https://osv.dev/vulnerability/CVE-2026-52880

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-52880/
Summaries are generated and may contain mistakes; the official description above is the record.