{"answers":{"affected":"1 open source package ship an affected version, including haproxy. It affects 1 product.","exploited":"It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-33555 exists.","fix":"Upgrade haproxy to 3.3.6 or later.","what":"CVE-2026-33555 is a medium-severity vulnerability in HAProxy, published on 13 Apr 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-2026-33555 and fix it if it is affected.\n\nWhat it is: CVE-2026-33555 is a medium-severity vulnerability in HAProxy, published on 13 Apr 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.\nExploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-33555 exists.\n\nAffected packages and fixed versions:\n- haproxy (Bitnami): affected from 2.6.0; fixed in 3.3.6\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-2026-33555/ (Markdown: https://insights.sbomify.com/CVE-2026-33555/index.md)","id":"CVE-2026-33555","markdown":"https://insights.sbomify.com/CVE-2026-33555/index.md","name":"CVE-2026-33555","record":{"aliases":["AZL-82730","BIT-haproxy-2026-33555","DEBIAN-CVE-2026-33555","GHSA-5mp8-rq5m-pj7m","MGASA-2026-0146","MINI-frr2-6qcm-2x7q","MINI-jm4x-3pq6-hxvm","OESA-2026-2083","OESA-2026-2084","OESA-2026-2085","OESA-2026-2086","RHSA-2026:8749","SUSE-SU-2026:1568-1","SUSE-SU-2026:21280-1","SUSE-SU-2026:21289-1","SUSE-SU-2026:21318-1","SUSE-SU-2026:21353-1","SUSE-SU-2026:21390-1","UBUNTU-CVE-2026-33555","openSUSE-SU-2026:10581-1","openSUSE-SU-2026:20618-1"],"analysis":{"component_type":"server_software","fix_type":"upgrade","impacts":["data_modify","security_bypass"],"network_reachable":"yes","non_default_config":false,"product_category":"HAProxy load balancer","requires_auth":"none","summary":"An attacker can exploit HTTP/3 parser flaws in HAProxy to cause request smuggling and desynchronize backend servers, potentially bypassing security controls.","user_interaction":"not_required","vuln_class":"other"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"mitre","cpe":[{"product":"haproxy","vendor":"haproxy"}],"cvss":{"score":4,"severity":"medium","source":"cna","vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:L/A:N","version":"3.1"},"cwes":[{"id":"CWE-130","name":"Improper Handling of Length Parameter Inconsistency"}],"description":"An issue was discovered in HAProxy before 3.3.6. The HTTP/3 parser does not check that the received body length matches a previously announced content-length when the stream is closed via a frame with an empty payload. This can cause desynchronization issues with the backend server and could be used for request smuggling. The earliest affected version is 2.6.","ecosystems":["Bitnami","Red Hat:hummingbird:1","SUSE:Linux Enterprise High Availability Extension 15 SP6","SUSE:Linux Enterprise High Availability Extension 15 SP7","SUSE:Linux Micro 6.2","openSUSE:Leap 16.0","openSUSE:Tumbleweed"],"exploits":{"exploitdb":0,"first_seen":"2026-04-16","github_poc":1,"max_poc_stars":2,"metasploit":0,"nuclei":0,"refs":[{"date":"2026-04-16T19:53:54Z","kind":"github_poc","ref":"https://github.com/r3verii/CVE-2026-33555","stars":2,"title":"One zero-byte QUIC packet is enough to desynchronize HAProxy's backend connection pool and smuggle HTTP requests across unrelated users — even users on a completely different frontend protocol."}],"tier":"weaponised"},"has_fix":true,"headline":"Other in HAProxy","id":"CVE-2026-33555","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":"Bitnami","product":null,"products":[],"type":"other","year":"2026"},"n_packages":7,"n_references":5,"next":{"headline":"Apache Kafka: Missing JWT token validation in OAUTHBEARER authentication","id":"CVE-2026-33557"},"packages":[{"ecosystem":"Bitnami","fixed":["3.3.6"],"introduced":["2.6.0"],"last_affected":[],"package":"haproxy","purl":"pkg:bitnami/haproxy","source":"BIT-haproxy-2026-33555"},{"ecosystem":"Red Hat:hummingbird:1","fixed":["0:3.0.19-1.1.hum1"],"introduced":["0"],"last_affected":[],"package":"haproxy","purl":"pkg:rpm/redhat/haproxy","source":"RHSA-2026:8749"},{"ecosystem":"SUSE:Linux Enterprise High Availability Extension 15 SP6","fixed":["2.8.11+git0.01c1056a4-150600.3.12.1"],"introduced":["0"],"last_affected":[],"package":"haproxy","purl":"pkg:rpm/suse/haproxy\u0026distro=SUSE%20Linux%20Enterprise%20High%20Availability%20Extension%2015%20SP6","source":"SUSE-SU-2026:1568-1"},{"ecosystem":"SUSE:Linux Enterprise High Availability Extension 15 SP7","fixed":["2.8.11+git0.01c1056a4-150600.3.12.1"],"introduced":["0"],"last_affected":[],"package":"haproxy","purl":"pkg:rpm/suse/haproxy\u0026distro=SUSE%20Linux%20Enterprise%20High%20Availability%20Extension%2015%20SP7","source":"SUSE-SU-2026:1568-1"},{"ecosystem":"SUSE:Linux Micro 6.2","fixed":["3.2.15+git64.0fc44b458-160000.2.1"],"introduced":["0"],"last_affected":[],"package":"haproxy","purl":"pkg:rpm/suse/haproxy\u0026distro=SUSE%20Linux%20Micro%206.2","source":"SUSE-SU-2026:21280-1"},{"ecosystem":"openSUSE:Leap 16.0","fixed":["3.2.15+git64.0fc44b458-160000.2.1"],"introduced":["0"],"last_affected":[],"package":"haproxy","purl":"pkg:rpm/opensuse/haproxy\u0026distro=openSUSE%20Leap%2016.0","source":"openSUSE-SU-2026:20618-1"},{"ecosystem":"openSUSE:Tumbleweed","fixed":["3.3.6+git91.af5637e93-1.1"],"introduced":["0"],"last_affected":[],"package":"haproxy","purl":"pkg:rpm/opensuse/haproxy\u0026distro=openSUSE%20Tumbleweed","source":"openSUSE-SU-2026:10581-1"}],"prev":{"headline":"Memory corruption in FreeIPMI","id":"CVE-2026-33554"},"products":["HAProxy"],"published":"2026-04-13","related":[{"cvss_score":9,"headline":"HAProxy - Integer Overflow in FCGI Demux Record Length Field","id":"CVE-2026-55203","kev_date_added":null,"published":"2026-06-18"},{"cvss_score":8.7,"headline":"HAProxy - NULL Pointer Dereference in hpack_dht_insert Function","id":"CVE-2026-55204","kev_date_added":null,"published":"2026-06-18"},{"cvss_score":8.2,"headline":"Information disclosure in n/a","id":"CVE-2023-45539","kev_date_added":null,"published":"2023-11-28"},{"cvss_score":7.5,"headline":"Denial of service in n/a","id":"CVE-2024-45506","kev_date_added":null,"published":"2024-09-04"},{"cvss_score":7.5,"headline":"Information disclosure in HAProxy","id":"CVE-2023-0836","kev_date_added":null,"published":"2023-03-29"},{"cvss_score":7.5,"headline":"Other in n/a","id":"CVE-2019-18277","kev_date_added":null,"published":"2019-10-23"},{"cvss_score":7.5,"headline":"Denial of service in n/a","id":"CVE-2019-14241","kev_date_added":null,"published":"2019-07-23"}],"sources":[{"class":"attribution","licence":"Apache-2.0","name":"Bitnami","prefix":"BIT"},{"class":"attribution","licence":"CVE Terms of Use (MITRE)","name":"CVE List","prefix":"CVE"},{"class":"attribution","licence":"CC BY 4.0","name":"Red Hat","prefix":"RHSA"},{"class":"attribution","licence":"CC BY 4.0","name":"SUSE","prefix":"SUSE"},{"class":"attribution","licence":"CC BY 4.0","name":"SUSE","prefix":"openSUSE"},{"class":"attribution","licence":"US public information, NVD API terms","name":"NVD"},{"class":"attribution","licence":"CWE Terms of Use","name":"CWE (MITRE)"},{"class":"attribution","licence":"FIRST CVSS licence","name":"CVSS (FIRST)"},{"class":"open","licence":"CC0","name":"PoC-in-GitHub"}],"ssvc":{"automatable":"no","exploitation":"poc","technical_impact":"partial"},"state":"PUBLISHED","updated":"2026-10-18","vendors":["HAProxy"]},"summary":"An attacker can exploit HTTP/3 parser flaws in HAProxy to cause request smuggling and desynchronize backend servers, potentially bypassing security controls.","url":"https://insights.sbomify.com/CVE-2026-33555/"}