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Vulnerability · Published May 8, 2026 · Assigned by EEF

CVE-2026-43967Quadratic fragment-name uniqueness check causes denial of service in absinthe

High 8.7

In plain English

A high-severity security flaw in absinthe from absinthe-graphql. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.6% (higher than 50% of all known vulnerabilities).

Severity (CVSS 4.0)8.7High
Exploit odds (30 days)0.6%top 49.9% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known

Official description

Inefficient Algorithmic Complexity vulnerability in absinthe-graphql absinthe allows unauthenticated denial of service via quadratic fragment-name uniqueness validation. 'Elixir.Absinthe.Phase.Document.Validation.UniqueFragmentNames':run/2 iterates over all fragments and for each one calls duplicate?/2, which evaluates Enum.count(fragments, &(&1.name == name)) — a full linear scan of the fragment list. The result is O(N²) comparisons per document, where N is the number of fragment definitions supplied by the caller. Because input.fragments is built directly from the GraphQL query body, N is fully attacker-controlled. A minimum-size fragment definition is roughly 16 bytes, so a ~1 MB document carries ~60,000 fragments and forces ~3.6 × 10⁹ comparisons inside this single validation phase. No authentication, schema knowledge, or special configuration is required. This issue affects absinthe: from 1.2.0 before 1.10.2.

Affected products (as reported)

VendorProductVersions
absinthe-graphql absinthe 1.2.0 – before 1.10.2
absinthe-graphql absinthe 0b46e3bcc06c0d3797bacd64761b908a84646c1d – before 223600c520493dcaf95080af552c413099f92c9d

Weakness: CWE-407 · Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

References