Apache CXF: FIQL Query Parser Denial of Service

CISA KEV is observed exploitation evidence. FIRST EPSS is a dated prediction of exploitation in the next 30 days. Missing scores are unknown. This collector requests predictions only for explicit CVE aliases in the public NuGet archive; Microsoft release views retain their existing prediction scope.

No collected risk observation for these identifiers. This does not establish absence of exploitation or a zero probability.

Apache CXF's FIQL query parser has a vulnerability in how it searches for operators in query expressions. The search pattern can get stuck trying many combinations when it encounters a long string without an operator, causing the parser to consume excessive CPU time. An attacker can send a crafted query to make the server use up CPU resources, potentially slowing down or stopping other requests. The fix was to limit FIQL expressions to 4 KiB by default, preventing attackers from sending extremely long inputs while still allowing normal queries. Users are recommended to upgrade to versions 4.2.4 or 4.1.9 or 3.6.13, which fix this issue.

Source published

9 Oct 2026 10:18:42 UTC

Source modified

15 Oct 2026 16:26:53 UTC

Observed here

23 Oct 2026 15:48:27 UTC

Source terms

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