Quick answers
- Is CVE-2026-76763 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-76763 being exploited in the wild.
- How severe is CVE-2026-76763?
- High severity, with a CVSS score of 7.5, published 31 August 2026.
- Which products and versions are affected?
- SmallRye GraphQL.
- Is there a fix for CVE-2026-76763?
- 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-2026-76763 attacked?
- It is attacked over the network.
- Am I affected by CVE-2026-76763?
- 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 SmallRye GraphQL's scalar coercion logic for BigInteger, which fails to properly validate the magnitude of float or string inputs before processing. An unauthenticated remote attacker can exploit this by sending a GraphQL query with a large-exponent float literal (e.g., 1e999999). The library attempts to coerce this into a BigInteger, triggering allocation of extremely large objects that exhaust CPU and heap memory, resulting in denial of service via OutOfMemoryError or CPU exhaustion. The parsing occurs before authorization checks, making this attack trivial to trigger. Mitigation includes using GraphQL variables instead of inline literals, implementing numeric precision validation, or adding rate-limiting and timeouts to the endpoint. A patch is expected from the SmallRye project.
Affected products
- SmallRye GraphQL
Timeline
- 2026-08-31: disclosed