CVE-2026-76763

Summary

A flaw was found in SmallRye GraphQL. The number scalar coercion for BigInteger does not properly validate the magnitude of float or string inputs. An unauthenticated remote attacker can exploit this by sending a GraphQL query containing a large exponent float literal. This can lead to the allocation of extremely large BigInteger objects, causing CPU exhaustion or an OutOfMemoryError, resulting in a denial of service.

Affected Software

VendorProductVersion RangeStatus

Weaknesses

  • CWE-1284: Improper Validation of Specified Quantity in Input

Workarounds

To mitigate this issue, applications exposing SmallRye GraphQL endpoints should implement validation and bounding of the precision or exponent for incoming numeric literals before they reach scalar coercion. Additionally, limiting the JVM heap size can help constrain the impact of OutOfMemoryError, though it will not prevent CPU exhaustion. Implementing rate-limiting or timeouts on the GraphQL endpoint can also reduce exposure. Using GraphQL variables instead of inline literals for numeric inputs is a safe alternative, as variables follow a secure parsing path.

ADP Enrichment

CISA ADP Vulnrichment

  • SSVC:
  • Exploitation: none
    • Automatable: yes
    • Technical Impact: partial

References