# CVE-2026-56708: Grav API Plugin before 1.0.16 SSRF via DNS Rebinding

> Attackers can bypass webhook hostname validation via DNS rebinding to access internal network resources in the Grav API plugin.

- **Severity:** Medium 6.9 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:L/SI:L/SA:L`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 25 Aug 2026
- **Updated:** 25 Aug 2026
- **Also known as:** GHSA-h2w4-jr6m-7c52

## What is CVE-2026-56708?

CVE-2026-56708 is a medium-severity server-side request forgery vulnerability in getgrav grav, published on 25 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Grav API plugin before 1.0.16 contains a server-side request forgery vulnerability in webhook delivery that allows attackers to bypass hostname validation by DNS rebinding. Attackers controlling authoritative DNS for a configured webhook hostname can answer validation lookups with public addresses and delivery lookups with private addresses to reach internal network resources.

Weakness: CWE-367 (Time-of-check Time-of-use (TOCTOU) Race Condition)

## Which versions are affected by CVE-2026-56708?


## How do I fix CVE-2026-56708?

No fix has been published for CVE-2026-56708 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-56708 being exploited?

There is no known exploitation of CVE-2026-56708 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-56708 and fix it if it is affected.

What it is: CVE-2026-56708 is a medium-severity server-side request forgery vulnerability in getgrav grav, published on 25 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-56708 in the wild and no public exploit code.

Affected product: getgrav grav. No package-level version data is available, so check the vendor advisory linked from the reference page.

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-2026-56708/ (Markdown: https://insights.sbomify.com/CVE-2026-56708/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-56708
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-56708
- OSV: https://osv.dev/vulnerability/CVE-2026-56708

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-56708/
Summaries are generated and may contain mistakes; the official description above is the record.