# CVE-2026-42793: Atom table exhaustion via attacker-controlled GraphQL SDL names in absinthe

> Unauthenticated attackers can crash the Erlang VM by exhausting the atom table via malicious GraphQL SDL names in Absinthe.

- **Severity:** High 8.2 (`CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 8 May 2026
- **Updated:** 9 May 2026
- **Also known as:** EEF-CVE-2026-42793, GHSA-qf4g-9fqq-mmm7

## What is CVE-2026-42793?

CVE-2026-42793 is a high-severity denial of service vulnerability in absinthe-graphql absinthe, published on 8 May 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Allocation of Resources Without Limits or Throttling vulnerability in absinthe-graphql absinthe allows unauthenticated denial of service via atom table exhaustion when parsing attacker-controlled GraphQL SDL.

Multiple Blueprint.Draft.convert/2 implementations in Absinthe's SDL language modules call String.to_atom/1 on attacker-controlled names from parsed GraphQL SDL documents, including directive names, field names, type names, and argument names. Because atoms are never garbage-collected and the BEAM atom table has a fixed limit (default 1,048,576), each unique name permanently consumes one slot. An attacker can exhaust the atom table by submitting SDL documents containing enough unique names, causing the Erlang VM to abort with system_limit and taking down the entire node.

Any application that passes attacker-controlled GraphQL SDL through Absinthe's parser is exposed — for example, a schema-upload endpoint, a federation gateway that ingests remote SDL, or any developer tool that runs the parser over user-supplied documents.

This issue affects absinthe: from 1.5.0 before 1.10.2.

Weakness: CWE-770 (Allocation of Resources Without Limits or Throttling)

## Which versions are affected by CVE-2026-42793?

3 open source packages ship an affected version, including absinthe. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `absinthe` | Hex | From 1.5.0 | 1.10.2 |
| `absinthe` | Hex | From 1.5.0 | 1.10.2 |
| `absinthe` | Hex | From 1.5.0 | 1.10.2 |

Products: Absinthe-Graphql Absinthe.

## How do I fix CVE-2026-42793?

Upgrade absinthe to 1.10.2 or later.

## Is CVE-2026-42793 being exploited?

There is no known exploitation of CVE-2026-42793 in the wild and no public exploit code.

## Other vulnerabilities in absinthe-graphql absinthe

- [CVE-2026-43967](https://insights.sbomify.com/CVE-2026-43967/): Quadratic fragment-name uniqueness check causes denial of service in absinthe (high 8.7)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-42793 and fix it if it is affected.

What it is: CVE-2026-42793 is a high-severity denial of service vulnerability in absinthe-graphql absinthe, published on 8 May 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-2026-42793 in the wild and no public exploit code.

Affected packages and fixed versions:
- absinthe (Hex): affected from 1.5.0; fixed in 1.10.2
- absinthe (Hex): affected from 1.5.0; fixed in 1.10.2
- absinthe (Hex): affected from 1.5.0; fixed in 1.10.2

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-2026-42793/ (Markdown: https://insights.sbomify.com/CVE-2026-42793/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-42793
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-42793
- OSV: https://osv.dev/vulnerability/CVE-2026-42793

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-42793/
Summaries are generated and may contain mistakes; the official description above is the record.