CVE-2023-44487
KEVMEDIUM 6.9EPSS 100.0%
The HTTP/2 protocol allows a denial of service (server resource consumption) because request cancellation can reset many streams quickly, as exploited in the wild in August through October 2023.
- CVSS v4.0 GitHub
- 6.9 MEDIUM
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:A - CVSS v3.1 NVD
- 7.5 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - CVSS v3.1 GitHub
- 5.3 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L/E:H - EPSS
- 100.00% chance of exploitation in the next 30 days, 100th percentile
- CISA KEV
- added 2023-10-10
- Published
- 2023-10-10
- Updated
- 2026-10-14
Proof-of-concept exploits (26)
- arkrwn/PoC/tree/main/CVE-2023-444873★ · 2023-10-12
- micrictor/http2-rst-stream6★ · 2023-10-11
- BMG-Black-Magic/CVE-2023-444870★ · 2025-02-19
- ByteHackr/CVE-2023-444870★ · 2023-10-12
- ReToCode/golang-CVE-2023-444872★ · 2023-10-26
- aulauniversal/CVE-2023-444871★ · 2025-01-18
- bcdannyboy/CVE-2023-44487248★ · 2024-01-08
- gmh5225/CVE_2023_44487-Rapid_Reset0★ · 2025-07-25
- imabee101/CVE-2023-4448756★ · 2023-10-13
- knabben/dos-poc5★ · 2024-04-16
- madhusudhan-in/CVE_2023_44487-Rapid_Reset1★ · 2026-08-05
- moften/CVE-2022-4174_CVE-2022-417420★ · 2025-03-31
- moften/CVE-2023-44487-HTTP-2-Rapid-Reset-Attack2★ · 2025-11-06
- nxenon/cve-2023-4448715★ · 2023-11-10
- oscerd/nice-cve-poc1★ · 2023-12-01
- sigridou/CVE-2023-44487-0★ · 2023-12-11
- studiogangster/CVE-2023-4448722★ · 2023-10-16
- threatlabindonesia/CVE-2023-44487-HTTP-2-Rapid-Reset-Exploit-PoC12★ · 2025-12-16
- zanks08/cve-2023-44487-demo1★ · 2025-04-22
- CerberusMrXi/CVE-2023-44487-HTTP2-DoS-Rapid-Reset-Exploit1★ · 2026-08-01
- ReGeLePuMa/HTTP-2-Rapid-Reset-DDos0★ · 2026-01-21
- tahaXafous/CVE-2023-44487-dos1★ · 2026-07-18
- tpirate/cve-2023-44487-POC2★ · 2025-12-14
- irvik00/Homework_110★ · 2026-02-12
- sub148/vuln-triage0★ · 2026-09-02
- whisper-cao/dsh-plugin-cvescout0★ · 2026-09-16
ExploitDB entries (1)
Security advisories
- https://access.redhat.com/security/cve/cve-2023-44487
- https://blog.cloudflare.com/technical-breakdown-http2-rapid-reset-ddos-attack
- https://blog.cloudflare.com/zero-day-rapid-reset-http2-record-breaking-ddos-attack
- https://blog.litespeedtech.com/2023/10/11/rapid-reset-http-2-vulnerablilty
- https://blog.vespa.ai/cve-2023-44487
- https://bugzilla.redhat.com/show_bug.cgi?id=2242803
- https://bugzilla.suse.com/show_bug.cgi?id=1216123
- https://cgit.freebsd.org/ports/commit/?id=c64c329c2c1752f46b73e3e6ce9f4329be6629f9
- https://cloud.google.com/blog/products/identity-security/google-cloud-mitigated-largest-d…
- https://cloud.google.com/blog/products/identity-security/how-it-works-the-novel-http2-rap…
- https://community.traefik.io/t/is-traefik-vulnerable-to-cve-2023-44487/20125
- https://forums.swift.org/t/swift-nio-http2-security-update-cve-2023-44487-http-2-dos/67764
- advisories/GHSA-qppj-fm5r-hxr3
- advisories/GHSA-vx74-f528-fxqg
- advisories/GHSA-xpw8-rcwv-8f8p
- caddyserver/caddy/issues/5877
- dotnet/announcements/issues/277
- h2o/h2o/security/advisories/GHSA-2m7v-gc89-fjqf
- https://groups.google.com/g/golang-announce/c/iNNxDTCjZvo
- https://istio.io/latest/news/security/istio-security-2023-004
- https://linkerd.io/2023/10/12/linkerd-cve-2023-44487
- https://msrc.microsoft.com/blog/2023/10/microsoft-response-to-distributed-denial-of-servi…
- https://msrc.microsoft.com/update-guide/vulnerability/CVE-2023-44487
- https://my.f5.com/manage/s/article/K000137106
- https://netty.io/news/2023/10/10/4-1-100-Final.html
- https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ht…
- https://security.paloaltonetworks.com/CVE-2023-44487
- https://ubuntu.com/security/CVE-2023-44487
- https://www.debian.org/security/2023/dsa-5521
- https://www.debian.org/security/2023/dsa-5522
- https://www.haproxy.com/blog/haproxy-is-not-affected-by-the-http-2-rapid-reset-attack-cve…
- https://www.netlify.com/blog/netlify-successfully-mitigates-cve-2023-44487
- https://www.nginx.com/blog/http-2-rapid-reset-attack-impacting-f5-nginx-products
- http://www.openwall.com/lists/oss-security/2023/10/10/6
- http://www.openwall.com/lists/oss-security/2023/10/10/7
- http://www.openwall.com/lists/oss-security/2023/10/13/4
- http://www.openwall.com/lists/oss-security/2023/10/13/9
- http://www.openwall.com/lists/oss-security/2023/10/18/4
- http://www.openwall.com/lists/oss-security/2023/10/18/8
- http://www.openwall.com/lists/oss-security/2023/10/19/6
- http://www.openwall.com/lists/oss-security/2023/10/20/8
- http://www.openwall.com/lists/oss-security/2025/08/13/6
- https://arstechnica.com/security/2023/10/how-ddosers-used-the-http-2-protocol-to-deliver-…
- https://aws.amazon.com/security/security-bulletins/AWS-2023-011
- https://blog.qualys.com/vulnerabilities-threat-research/2023/10/10/cve-2023-44487-http-2-…
- https://bugzilla.proxmox.com/show_bug.cgi?id=4988
- https://cert-portal.siemens.com/productcert/html/ssa-082556.html
- https://cert-portal.siemens.com/productcert/html/ssa-341067.html
- https://cert-portal.siemens.com/productcert/html/ssa-784301.html
- https://cert-portal.siemens.com/productcert/html/ssa-832273.html
- https://cert-portal.siemens.com/productcert/html/ssa-915275.html
- https://discuss.hashicorp.com/t/hcsec-2023-32-vault-consul-and-boundary-affected-by-http-…
- apache/tomcat/tree/main/java/org/apache/coyote/http2
- https://lists.debian.org/debian-lts-announce/2023/10/msg00020.html
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/…
- https://lists.w3.org/Archives/Public/ietf-http-wg/2023OctDec/0025.html
- https://mailman.nginx.org/pipermail/nginx-devel/2023-October/S36Q5HBXR7CAIMPLLPRSSSYR4PCM…
- https://martinthomson.github.io/h2-stream-limits/draft-thomson-httpbis-h2-stream-limits.h…
- https://openssf.org/blog/2023/10/10/http-2-rapid-reset-vulnerability-highlights-need-for-…
- https://seanmonstar.com/post/730794151136935936/hyper-http2-rapid-reset-unaffected
- https://security.gentoo.org/glsa/202311-09
- https://security.netapp.com/advisory/ntap-20231016-0001
- https://security.netapp.com/advisory/ntap-20240426-0007
- https://security.netapp.com/advisory/ntap-20240621-0006
- https://security.netapp.com/advisory/ntap-20240621-0007
- https://www.bleepingcomputer.com/news/security/new-http-2-rapid-reset-zero-day-attack-bre…
- https://www.cisa.gov/news-events/alerts/2023/10/10/http2-rapid-reset-vulnerability-cve-20…
- https://www.darkreading.com/cloud/internet-wide-zero-day-bug-fuels-largest-ever-ddos-event
- https://www.debian.org/security/2023/dsa-5540
- https://www.debian.org/security/2023/dsa-5549
- https://www.debian.org/security/2023/dsa-5558
- https://www.debian.org/security/2023/dsa-5570
- https://www.openwall.com/lists/oss-security/2023/10/10/6
- https://www.theregister.com/2023/10/10/http2_rapid_reset_zeroday
- https://www.vicarius.io/vsociety/posts/rapid-reset-cve-2023-44487-dos-in-http2-understand…
- https://gist.github.com/adulau/7c2bfb8e9cdbe4b35a5e131c66a0c088
- apache/trafficserver/pull/10564
- envoyproxy/envoy/pull/30055
- etcd-io/etcd/issues/16740
- facebook/proxygen/pull/466
- grpc/grpc-go/pull/6703
- h2o/h2o/pull/3291
- kazu-yamamoto/http2/issues/93
- kubernetes/kubernetes/pull/121120
- line/armeria/pull/5232
- linkerd/website/pull/1695/commits/4b9c6836471bc8270ab48aae6fd2181bc73fd632
- microsoft/CBL-Mariner/pull/6381
- netty/netty/commit/58f75f665aa81a8cbcf6ffa74820042a285c5e61
- nghttp2/nghttp2/pull/1961
- opensearch-project/data-prepper/issues/3474
- projectcontour/contour/pull/5826
- dotnet/core/blob/e4613450ea0da7fd2fc6b61dfb2c1c1dec1ce9ec/release-notes/6.0/6.0.23/6.0.23…
- https://tomcat.apache.org/security-10.html#Fixed_in_Apache_Tomcat_10.1.14
- apache/httpd/blob/afcdbeebbff4b0c50ea26cdd16e178c0d1f24152/modules/http2/h2_mplx.c#L1101-…
- icing/mod_h2/blob/0a864782af0a942aa2ad4ed960a6b32cd35bcf0a/mod_http2/README.md?plain=1#L2…
- Azure/AKS/issues/3947
- Kong/kong/discussions/11741
- akka/akka-http/issues/4323
- alibaba/tengine/issues/1872
- apache/apisix/issues/10320
- apache/httpd-site/pull/10
- eclipse/jetty.project/issues/10679
- golang/go/issues/63417
- haproxy/haproxy/issues/2312
- junkurihara/rust-rpxy/issues/97
- ninenines/cowboy/issues/1615
- nodejs/node/pull/50121
- openresty/openresty/issues/930
- oqtane/oqtane.framework/discussions/3367
- tempesta-tech/tempesta/issues/1986
- varnishcache/varnish-cache/issues/3996
- https://news.ycombinator.com/item?id=37830987
- https://news.ycombinator.com/item?id=37830998
- https://news.ycombinator.com/item?id=37831062
- https://news.ycombinator.com/item?id=37837043