CVE-2026-76763

Io.smallrye/smallrye-graphql: smallrye graphql: unauthenticated denial of service via large exponent float literals

Published Aug 31, 2026 CVSS 3.1 · 7.5 High EPSS < 1% KEV · Not listed
Description
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.

Remediation

Vendor Workaround

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.

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
CPEs cpe:/a:redhat:quarkus:3 cpe:/a:redhat:quarkus:3.27
cpe:/a:redhat:quarkus:3.33
References
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
First Time appeared Redhat build Of Quarkus
Vendors & Products Redhat build Of Quarkus
Type Values Removed Values Added
Description 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.
Title Io.smallrye/smallrye-graphql: smallrye graphql: unauthenticated denial of service via large exponent float literals
First Time appeared Redhat
Redhat quarkus
Weaknesses CWE-1284
CPEs cpe:/a:redhat:quarkus:3
Vendors & Products Redhat
Redhat quarkus
References
Metrics cvssV3_1

{'score': 7.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
redhat
Published
Updated
Oct 20, 2026, 4:32 AM
Reserved
Aug 19, 2026, 4:58 PM
Status
Awaiting Analysis
Published
Aug 31, 2026, 2:17 PM
Modified
Oct 20, 2026, 5:16 AM
Severity
Important
Public date
Aug 31, 2026, 11:58 AM