{"answers":{"affected":"8 open source packages ship an affected version, including org.http4s:http4s-blaze-server_2.13, org.http4s:http4s-blaze-server_2.12 and org.http4s:http4s-blaze-server_3.","exploited":"There is no known exploitation of CVE-2026-73493 in the wild and no public exploit code.","fix":"Upgrade org.http4s:http4s-blaze-server_2.13 to a fixed version for your release line: 0.23.18 or 1.0.0-M42.","what":"CVE-2026-73493 is a high-severity denial of service vulnerability in http4s blaze, published on 12 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim."},"fix_prompt":"Check this codebase for CVE-2026-73493 and fix it if it is affected.\n\nWhat it is: CVE-2026-73493 is a high-severity denial of service vulnerability in http4s blaze, published on 12 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.\nExploitation: There is no known exploitation of CVE-2026-73493 in the wild and no public exploit code.\n\nAffected packages and fixed versions:\n- org.http4s:http4s-blaze-server_2.13 (Maven): affected all versions; fixed in 0.23.18\n- org.http4s:http4s-blaze-server_2.13 (Maven): affected all versions; fixed in 0.23.18\n- org.http4s:http4s-blaze-server_2.13 (Maven): affected from 1.0.0-M1; fixed in 1.0.0-M42\n- org.http4s:http4s-blaze-server_2.13 (Maven): affected from 1.0.0-M1; fixed in 1.0.0-M42\n- org.http4s:http4s-blaze-server_2.12 (Maven): affected all versions; fixed in 0.23.18\n- org.http4s:http4s-blaze-server_2.12 (Maven): affected all versions; fixed in 0.23.18\n- org.http4s:http4s-blaze-server_3 (Maven): affected from 1.0.0-M1; fixed in 1.0.0-M42\n- org.http4s:http4s-blaze-server_3 (Maven): affected from 1.0.0-M1; fixed in 1.0.0-M42\n\nTask:\n1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.\n2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.\n3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.\n4. Run the tests and summarise what changed and why.\n5. If nothing in the project is affected, say so and change nothing.\n\nReference: https://insights.sbomify.com/CVE-2026-73493/ (Markdown: https://insights.sbomify.com/CVE-2026-73493/index.md)","id":"CVE-2026-73493","markdown":"https://insights.sbomify.com/CVE-2026-73493/index.md","name":"CVE-2026-73493","record":{"aliases":["GHSA-7ppr-r889-mcf2"],"analysis":{"component_type":"library","fix_type":"upgrade","impacts":["denial_of_service"],"network_reachable":"yes","non_default_config":false,"product_category":"Scala HTTP library","requires_auth":"none","summary":"Attackers can cause server crashes via unbounded WebSocket message aggregation in http4s-blaze-server, requiring an upgrade to fix.","user_interaction":"not_required","vuln_class":"denial_of_service"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"GitHub_M","cpe":[],"cvss":{"score":7.5,"severity":"high","source":"cna","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","version":"3.1"},"cwes":[{"id":"CWE-770","name":"Allocation of Resources Without Limits or Throttling"}],"description":"Http4s (http4s-blaze-server) is a minimal, idiomatic Scala interface for HTTP services. Prior to 0.23.18 and 1.0.0-M42, http4s-blaze-server aggregates fragments of an incoming WebSocket message with no limit on total size or fragment count. A client that completes a WebSocket handshake can send an unterminated fragmented message and drive unbounded heap growth in the server JVM, resulting in denial of service through OutOfMemoryError. Any http4s application serving WebSocket routes over BlazeServerBuilder is affected, no non-default configuration is required, and maxWebSocketBufferSize does not bound the aggregate because it bounds only individual frames. A single connection sending continuation frames that never set FIN forces the server to buffer every fragment until the heap is exhausted, terminating the JVM with OutOfMemoryError on the blaze selector thread. Small fragments amplify the cost through per-frame object overhead, so a modest volume of wire bytes is sufficient. This issue is fixed in versions 0.23.18 and 1.0.0-M42.","ecosystems":["Maven"],"exploits":{"exploitdb":0,"first_seen":null,"github_poc":0,"max_poc_stars":null,"metasploit":0,"nuclei":0,"refs":[],"tier":"none_known"},"has_fix":true,"headline":"http4s-blaze-server: Unbounded WebSocket message aggregation","id":"CVE-2026-73493","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":"Maven","product":null,"products":[],"type":"denial_of_service","year":"2026"},"n_packages":8,"n_references":4,"next":{"headline":"blaze: Multiple HTTP/1.1 request-smuggling primitives in blaze's Java wire parser","id":"CVE-2026-73494"},"packages":[{"ecosystem":"Maven","fixed":["0.23.18"],"introduced":["0"],"last_affected":[],"package":"org.http4s:http4s-blaze-server_2.12","purl":null,"source":"GHSA-7ppr-r889-mcf2"},{"ecosystem":"Maven","fixed":["0.23.18"],"introduced":["0"],"last_affected":[],"package":"org.http4s:http4s-blaze-server_2.12","purl":"pkg:maven/org.http4s/http4s-blaze-server_2.12","source":"GHSA-7ppr-r889-mcf2"},{"ecosystem":"Maven","fixed":["0.23.18"],"introduced":["0"],"last_affected":[],"package":"org.http4s:http4s-blaze-server_2.13","purl":null,"source":"GHSA-7ppr-r889-mcf2"},{"ecosystem":"Maven","fixed":["0.23.18"],"introduced":["0"],"last_affected":[],"package":"org.http4s:http4s-blaze-server_2.13","purl":"pkg:maven/org.http4s/http4s-blaze-server_2.13","source":"GHSA-7ppr-r889-mcf2"},{"ecosystem":"Maven","fixed":["1.0.0-M42"],"introduced":["1.0.0-M1"],"last_affected":[],"package":"org.http4s:http4s-blaze-server_2.13","purl":null,"source":"GHSA-7ppr-r889-mcf2"},{"ecosystem":"Maven","fixed":["1.0.0-M42"],"introduced":["1.0.0-M1"],"last_affected":[],"package":"org.http4s:http4s-blaze-server_2.13","purl":"pkg:maven/org.http4s/http4s-blaze-server_2.13","source":"GHSA-7ppr-r889-mcf2"},{"ecosystem":"Maven","fixed":["1.0.0-M42"],"introduced":["1.0.0-M1"],"last_affected":[],"package":"org.http4s:http4s-blaze-server_3","purl":null,"source":"GHSA-7ppr-r889-mcf2"},{"ecosystem":"Maven","fixed":["1.0.0-M42"],"introduced":["1.0.0-M1"],"last_affected":[],"package":"org.http4s:http4s-blaze-server_3","purl":"pkg:maven/org.http4s/http4s-blaze-server_3","source":"GHSA-7ppr-r889-mcf2"}],"prev":{"headline":"Loofah `allowed_uri?` does not detect `javascript:` URIs split by numeric character references without semicolons","id":"CVE-2026-73492"},"products":["blaze"],"published":"2026-08-12","related":[],"sources":[{"class":"attribution","licence":"CVE Terms of Use (MITRE)","name":"CVE List","prefix":"CVE"},{"class":"attribution","licence":"CC BY 4.0","name":"GitHub Advisory Database","prefix":"GHSA"},{"class":"attribution","licence":"CWE Terms of Use","name":"CWE (MITRE)"},{"class":"attribution","licence":"FIRST CVSS licence","name":"CVSS (FIRST)"}],"ssvc":{"automatable":"yes","exploitation":"none","technical_impact":"partial"},"state":"PUBLISHED","updated":"2026-08-13","vendors":["http4s"]},"summary":"Attackers can cause server crashes via unbounded WebSocket message aggregation in http4s-blaze-server, requiring an upgrade to fix.","url":"https://insights.sbomify.com/CVE-2026-73493/"}