CVE-2026-43967: Absinthe-graphql Absinthe vulnerability (CVSS 7.5)

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.

CVSS 3.1 breakdown

Attack vectorNetwork

Attack complexityLow

Privileges requiredNone

User interactionNone

ScopeUnchanged

ConfidentialityNone

IntegrityNone

AvailabilityHigh

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected products

Absinthe-graphql Absinthe> 1.2.0 < 1.10.2

Remediation

Fixed in

Absinthe-graphql Absinthe≥ 1.10.2

Patch & vendor advisories

References

https://cna.erlef.org/cves/CVE-2026-43967.htmlPatchThird Party Advisory
https://github.com/absinthe-graphql/absinthe/commit/223600c520493dcaf95080af552c413099f92c9dPatch
https://github.com/absinthe-graphql/absinthe/security/advisories/GHSA-9mhv-8h52-q7q2ExploitVendor Advisory
https://osv.dev/vulnerability/EEF-CVE-2026-43967Third Party Advisory

Related CVEs

Recent high-severity vulnerabilities sharing a weakness type.

Frequently asked

Is CVE-2026-43967 being actively exploited?

CVE-2026-43967 is not in the CISA KEV catalog. A public exploit reference exists, so treat it as exploitable. Its EPSS exploit probability is 0.82%.

How severe is CVE-2026-43967?

CVE-2026-43967 has a CVSS 3.1 base score of 7.5, rated high. EPSS estimates a 0.82% probability of exploitation.

Which products are affected by CVE-2026-43967?

Affected products include Absinthe-graphql Absinthe.

How do I fix CVE-2026-43967?

Upgrade affected software to a fixed version, for example Absinthe-graphql Absinthe 1.10.2 or later, then confirm no affected versions remain in your inventory.

How Secuno handles this

Secuno correlates vulnerabilities like CVE-2026-43967 against the real software inventory on every managed device, as each hourly inventory arrives. Rather than a static severity, each match is scored in context: exploit availability, EPSS, the asset's exposure, and business criticality decide where it lands in the queue. If an affected version is present anywhere across your portfolio, it surfaces automatically with a prioritised remediation path.

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