CISA KEV · catalog date Oct 10, 2023 · first observed Sep 1, 2026
Evidence dossier
CVE-2023-44487
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…
Exploited in the wild (CISA KEV since Oct 10, 2023). NVD reports CVSS 3.1 7.5. EPSS estimates 100.0% exploit likelihood as of Oct 20, 2026.
As of Oct 22, 2026
Normalized restatement
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.
- State
- PUBLISHED
- Published
- Oct 10, 2023
- Updated
- Oct 14, 2026
- Evidence coverage
- 85%
Evidence chronology
What was known when
- Source dateFirst observed by CASCACISA KEVOriginal evidence ↗
Exploitation cataloged: HTTP/2 Rapid Reset Attack Vulnerability
Inspect raw assertion
- Field
observed_exploitation- Value
- HTTP/2 Rapid Reset Attack Vulnerability
- Source dateSource date omittedFirst observed by CASCACISA-ADPOriginal evidence ↗
Record text: CISA ADP Vulnrichment
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- Field
container- Value
- CISA ADP Vulnrichment
- Source dateSource date omittedFirst observed by CASCACVE ProgramOriginal evidence ↗
Record text: CVE Program Container
Inspect raw assertion
- Field
container- Value
- CVE Program Container
- Source dateSource date omittedFirst observed by CASCAmitreOriginal evidence ↗
Record text: 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.
Inspect raw assertion
- Field
container- Value
- 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.
- Source dateSource date omittedFirst observed by CASCAsiemens-SADPOriginal evidence ↗
Record text: Container present
Inspect raw assertion
- Field
container- Value
- Container present
- Source dateFirst observed by CASCAFIRST EPSSOriginal evidence ↗
EPSS score: 100% probability · 100th percentile
Inspect raw assertion
- Field
model_probability- Value
- Probability 0.999990000000; percentile 0.999990000000
FIRST EPSS · score date Oct 20, 2026 · 100th percentile · first observed Oct 20, 2026
NVD · CVSS 3.1 · first observed Aug 11, 2026 · same-version scores align in this snapshot
Evidence detail
Source limits and decisions
Why each evidence state has this value
Outside this view’s verified evidenceReason detail begins outside this selected snapshot; the state remains source-bound.
Source comparison
Who said what
HTTP/2 Rapid Reset Attack Vulnerability
Inspect raw assertion
- Field
observed_exploitation- Value
- HTTP/2 Rapid Reset Attack Vulnerability
CISA ADP Vulnrichment
Inspect raw assertion
- Field
container- Value
- CISA ADP Vulnrichment
CVE Program Container
Inspect raw assertion
- Field
container- Value
- CVE Program Container
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.
Inspect raw assertion
- Field
container- Value
- 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.
Container present
Inspect raw assertion
- Field
container- Value
- Container present
100% probability · 100th percentile
Inspect raw assertion
- Field
model_probability- Value
- Probability 0.999990000000; percentile 0.999990000000
Applicability
Cited product scope
Grouped from 52 configuration nodes in this exact snapshot. Visual grouping is navigational; asset exposure and root cause require cited evidence.
Identity source boundaries
- Cpe dictionary1,775,266 records · observed through 2026-07-21T06:45:29.809Z
27d65b0f-b718-4b4f-bb79-c47c68d09dfa - Cpe match643,502 records · observed through 2026-07-21T08:13:17.697Z
955dae73-7302-438b-aee1-058d7cc5d48e
334 scope groups
Canonical linkage remains open; the cited source assertion is retained below.
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[{"status": "affected", "version": "2.0"}]Canonical linkage remains open; the cited source assertion is retained below.
Inspect raw assertion
[{"status": "affected", "version": "n/a"}]Canonical linkage remains open; the cited source assertion is retained below.
Inspect raw assertion
[{"status": "affected", "version": "0", "lessThan": "*", "versionType": "custom"}]Canonical linkage remains open; the cited source assertion is retained below.
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[{"status": "affected", "version": "V3.1.5", "lessThan": "*", "versionType": "custom"}]Canonical linkage remains open; the cited source assertion is retained below.
Inspect raw assertion
[{"status": "affected", "version": "V3.1.5", "lessThan": "*", "versionType": "custom"}]Canonical linkage remains open; the cited source assertion is retained below.
Inspect raw assertion
[{"status": "affected", "version": "V3.1.5", "lessThan": "*", "versionType": "custom"}]Canonical linkage remains open; the cited source assertion is retained below.
Inspect raw assertion
[{"status": "affected", "version": "V3.1.5", "lessThan": "*", "versionType": "custom"}]Canonical linkage remains open; the cited source assertion is retained below.
Inspect raw assertion
[{"status": "affected", "version": "0", "lessThan": "V3.0", "versionType": "custom"}]Canonical linkage remains open; the cited source assertion is retained below.
Inspect raw assertion
[{"status": "affected", "version": "V3.1.5", "lessThan": "*", "versionType": "custom"}]product-9776d53f82f44173c196d4c32d62e08ba7e5a2d28c4571d3d9541f066a369672Linked exactInspect raw assertion
cpe:2.3:a:akka:http_server:*:*:*:*:*:*:*:*- Official link
- Linked exact
- Role
- Vulnerable target
- Configuration
- 35 · node/0 · match 0
- Logic
- OR
- Version bounds
- through excluding 10.5.3
- Match ID
c2792650-851f-4820-b003-06a4bea092d7
product-b830e5a86146ab82d53e34102b7e2666aa59c2c48a3b942ca0f2bce8c40be868Linked exactInspect raw assertion
cpe:2.3:a:amazon:opensearch_data_prepper:*:*:*:*:*:*:*:*- Official link
- Linked exact
- Role
- Vulnerable target
- Configuration
- 22 · node/0 · match 0
- Logic
- OR
- Version bounds
- through excluding 2.5.0
- Match ID
6f70360d-6214-46ba-af82-6ab01e13e4e9
product-caed4e90c360cff225b5314e1a6a2793deed8338c5c3912d0a901cd560df6f42Linked exactInspect raw assertion
cpe:2.3:a:apache:apisix:*:*:*:*:*:*:*:*- Official link
- Linked exact
- Role
- Vulnerable target
- Configuration
- 21 · node/0 · match 0
- Logic
- OR
- Version bounds
- through excluding 3.6.1
- Match ID
edeb508e-0ebd-4450-9074-983ddf568ab4
product-b2893c436d20eeea3899b65735644a7c662137429e9b2fba8a3cdbf6d307d1afLinked exactInspect raw assertion
cpe:2.3:a:apache:solr:*:*:*:*:*:*:*:*- Official link
- Linked exact
- Role
- Vulnerable target
- Configuration
- 38 · node/0 · match 0
- Logic
- OR
- Version bounds
- through excluding 9.4.0
- Match ID
8e1affb9-c717-4727-b0c9-5a0c281710e2
product-b4642eb973ddbe1a3e24c089bf036c528ab40d12c3eab0fae6fd551615375441Linked exactInspect raw assertions
cpe:2.3:a:apache:tomcat:11.0.0:milestone1:*:*:*:*:*:*- Official link
- Linked exact
- Role
- Vulnerable target
- Configuration
- 13 · node/0 · match 3
- Logic
- OR
- Version bounds
- No explicit bounds
- Match ID
d1aa7ff6-e8e7-4bf6-983e-0a99b0183008
cpe:2.3:a:apache:tomcat:11.0.0:milestone6:*:*:*:*:*:*- Official link
- Linked exact
- Role
- Vulnerable target
- Configuration
- 13 · node/0 · match 10
- Logic
- OR
- Version bounds
- No explicit bounds
- Match ID
49350a6e-5e1d-45b2-a874-3b8601b3adcc
cpe:2.3:a:apache:tomcat:11.0.0:milestone2:*:*:*:*:*:*- Official link
- Linked exact
- Role
- Vulnerable target
- Configuration
- 13 · node/0 · match 6
- Logic
- OR
- Version bounds
- No explicit bounds
- Match ID
2aad52ce-94f5-4f98-a027-9a7e68818cb6
cpe:2.3:a:apache:tomcat:11.0.0:milestone7:*:*:*:*:*:*- Official link
- Linked exact
- Role
- Vulnerable target
- Configuration
- 13 · node/0 · match 11
- Logic
- OR
- Version bounds
- No explicit bounds
- Match ID
5f50942f-df54-46c0-8371-9a476dd3eea3
cpe:2.3:a:apache:tomcat:*:*:*:*:*:*:*:*- Official link
- Linked exact
- Role
- Vulnerable target
- Configuration
- 13 · node/0 · match 1
- Logic
- OR
- Version bounds
- from including 9.0.0; through including 9.0.80
- Match ID
f3ec20b6-b2ab-41f5-9bf9-d16c1fe67c34
cpe:2.3:a:apache:tomcat:11.0.0:milestone10:*:*:*:*:*:*- Official link
- Linked exact
- Role
- Vulnerable target
- Configuration
- 13 · node/0 · match 4
- Logic
- OR
- Version bounds
- No explicit bounds
- Match ID
57088bdd-a136-45ef-a8a1-2ebf79cec2ce
cpe:2.3:a:apache:tomcat:11.0.0:milestone4:*:*:*:*:*:*- Official link
- Linked exact
- Role
- Vulnerable target
- Configuration
- 13 · node/0 · match 8
- Logic
- OR
- Version bounds
- No explicit bounds
- Match ID
03a171af-2ec8-4422-912c-547cdb58caaa
cpe:2.3:a:apache:tomcat:11.0.0:milestone8:*:*:*:*:*:*- Official link
- Linked exact
- Role
- Vulnerable target
- Configuration
- 13 · node/0 · match 12
- Logic
- OR
- Version bounds
- No explicit bounds
- Match ID
d12c2c95-b79f-4aa4-8ce3-99a3ee7991ab
cpe:2.3:a:apache:tomcat:11.0.0:milestone3:*:*:*:*:*:*- Official link
- Linked exact
- Role
- Vulnerable target
- Configuration
- 13 · node/0 · match 7
- Logic
- OR
- Version bounds
- No explicit bounds
- Match ID
f1f981f5-035a-4edd-8a9f-481ee8bc7ff7
cpe:2.3:a:apache:tomcat:11.0.0:milestone11:*:*:*:*:*:*- Official link
- Linked exact
- Role
- Vulnerable target
- Configuration
- 13 · node/0 · match 5
- Logic
- OR
- Version bounds
- No explicit bounds
- Match ID
b32d1d7a-a04f-444e-8f45-bb9a9e4b0199
cpe:2.3:a:apache:tomcat:11.0.0:milestone5:*:*:*:*:*:*- Official link
- Linked exact
- Role
- Vulnerable target
- Configuration
- 13 · node/0 · match 9
- Logic
- OR
- Version bounds
- No explicit bounds
- Match ID
538e68c4-0ba4-495f-aef8-4ef6ee7963cf
cpe:2.3:a:apache:tomcat:*:*:*:*:*:*:*:*- Official link
- Linked exact
- Role
- Vulnerable target
- Configuration
- 13 · node/0 · match 2
- Logic
- OR
- Version bounds
- from including 10.1.0; through including 10.1.13
- Match ID
0765cc3d-ab1a-4147-8900-ef4c105321f2
cpe:2.3:a:apache:tomcat:*:*:*:*:*:*:*:*- Official link
- Linked exact
- Role
- Vulnerable target
- Configuration
- 13 · node/0 · match 0
- Logic
- OR
- Version bounds
- from including 8.5.0; through including 8.5.93
- Match ID
abd26b48-cc80-4fae-bd3d-78de4c80c92b
cpe:2.3:a:apache:tomcat:11.0.0:milestone9:*:*:*:*:*:*- Official link
- Linked exact
- Role
- Vulnerable target
- Configuration
- 13 · node/0 · match 13
- Logic
- OR
- Version bounds
- No explicit bounds
- Match ID
98792138-dd56-42df-9612-3bdc65eec117
product-c42bc7eba6af637a13fb54eab5f94bd3e9e3419eb58b3129923d3cdd9a5c0ef6Linked exactInspect raw assertions
cpe:2.3:a:apache:traffic_server:*:*:*:*:*:*:*:*- Official link
- Linked exact
- Role
- Vulnerable target
- Configuration
- 21 · node/0 · match 1
- Logic
- OR
- Version bounds
- from including 8.0.0; through excluding 8.1.9
- Match ID
93a1a748-6c71-4191-8a16-a93e94e2cde4
cpe:2.3:a:apache:traffic_server:*:*:*:*:*:*:*:*- Official link
- Linked exact
- Role
- Vulnerable target
- Configuration
- 21 · node/0 · match 2
- Logic
- OR
- Version bounds
- from including 9.0.0; through excluding 9.2.3
- Match ID
4e4bcaf6-b246-41ec-9ee1-24296bfc4f5a
product-0ca8c293371722f491e234d0bb6b9c183287ad109f0ea981c8a026055c733a11Linked exactInspect raw assertion
cpe:2.3:a:apple:swiftnio_http\/2:*:*:*:*:*:swift:*:*- Official link
- Linked exact
- Role
- Vulnerable target
- Configuration
- 14 · node/0 · match 0
- Logic
- OR
- Version bounds
- through excluding 1.28.0
- Match ID
08190072-3880-4ef5-b642-ba053090d95b
product-a3ce70be7384b3b896eed19051027b0619c4836b397ccb0e3ed214b628c3207aLinked exactInspect raw assertion
cpe:2.3:a:caddyserver:caddy:*:*:*:*:*:*:*:*- Official link
- Linked exact
- Role
- Vulnerable target
- Configuration
- 10 · node/0 · match 0
- Logic
- OR
- Version bounds
- through excluding 2.7.5
- Match ID
6341ddda-ad27-4087-9d59-0a212f0037b4
product-364e1e4d7e29948d0c858987580f80a37236abf4b7817e9e28346fe5956cc208Linked exactInspect raw assertion
cpe:2.3:a:cisco:business_process_automation:*:*:*:*:*:*:*:*- Official link
- Linked exact
- Role
- Vulnerable target
- Configuration
- 40 · node/0 · match 0
- Logic
- OR
- Version bounds
- through excluding 3.2.003.009
- Match ID
fb2bdbac-8d19-4f81-8d31-6d0955a53d82
product-dc7d7adfe50f1fd081ca3b9776e4791a048f385df865e8fbca88705b5cf42e33Linked exactInspect raw assertion
cpe:2.3:a:cisco:connected_mobile_experiences:*:*:*:*:*:*:*:*- Official link
- Linked exact
- Role
- Vulnerable target
- Configuration
- 40 · node/0 · match 1
- Logic
- OR
- Version bounds
- through excluding 11.1
- Match ID
f98f9d27-6659-413f-8f29-4fdb0882aac5
product-92616884c37306fc8794ae010618f83d6050f2570e1ee05f20d936b5324614d1Linked exactInspect raw assertions
cpe:2.3:a:cisco:crosswork_data_gateway:*:*:*:*:*:*:*:*- Official link
- Linked exact
- Role
- Vulnerable target
- Configuration
- 40 · node/0 · match 3
- Logic
- OR
- Version bounds
- from including 5.0.0; through excluding 5.0.2
- Match ID
3f30e209-fa52-4d3b-9b88-4193ea388554
cpe:2.3:a:cisco:crosswork_data_gateway:*:*:*:*:*:*:*:*- Official link
- Linked exact
- Role
- Vulnerable target
- Configuration
- 40 · node/0 · match 2
- Logic
- OR
- Version bounds
- through excluding 4.1.3
- Match ID
c98bf315-c563-47c2-bad1-63347a3d1008
product-463dd0156b0589555287f4e1c346f3190b2d3333b1111f1782019d2ff9dd577fLinked exactInspect raw assertion
cpe:2.3:a:cisco:crosswork_situation_manager:-:*:*:*:*:*:*:*- Official link
- Linked exact
- Role
- Vulnerable target
- Configuration
- 40 · node/0 · match 4
- Logic
- OR
- Version bounds
- No explicit bounds
- Match ID
3178f3a5-a072-44e1-a225-b04bc536f4fb
product-07d1911e5dfe73ef44ee2ed85187496b5a431e58793cac536dfcd97a4587f973Linked exactInspect raw assertion
cpe:2.3:a:cisco:crosswork_zero_touch_provisioning:*:*:*:*:*:*:*:*- Official link
- Linked exact
- Role
- Vulnerable target
- Configuration
- 40 · node/0 · match 5
- Logic
- OR
- Version bounds
- through excluding 6.0.0
- Match ID
aa2be0f1-dd16-4876-8eba-f187bd38b159
product-820da73e8b1ce20a148c02808326fc3d77735d2e6ad9ea94c13e16c5de944840Linked exactInspect raw assertion
cpe:2.3:a:cisco:data_center_network_manager:-:*:*:*:*:*:*:*- Official link
- Linked exact
- Role
- Vulnerable target
- Configuration
- 40 · node/0 · match 6
- Logic
- OR
- Version bounds
- No explicit bounds
- Match ID
796b6c58-2140-4105-a2a1-69865a194a75
product-129eab901ba327e52cee2d1cc1cae44edf100fdb576a36c4d01455a2bb1517afLinked exactInspect raw assertion
cpe:2.3:a:cisco:enterprise_chat_and_email:-:*:*:*:*:*:*:*- Official link
- Linked exact
- Role
- Vulnerable target
- Configuration
- 40 · node/0 · match 7
- Logic
- OR
- Version bounds
- No explicit bounds
- Match ID
dea99dc6-ea03-469f-a8be-7f96fdf0b333
product-042d135e36637e89339aad298e5307d2741962385320af758c1b2746c7c56eadLinked exactInspect raw assertion
cpe:2.3:a:cisco:expressway:*:*:*:*:*:*:*:*- Official link
- Linked exact
- Role
- Vulnerable target
- Configuration
- 40 · node/0 · match 8
- Logic
- OR
- Version bounds
- through excluding x14.3.3
- Match ID
6560dbf4-afe6-4672-95de-74a0b8f4170a
Affected-product evidence
Accepted scope and product mapping
0 canonical links · 0 source-reported links
Applicability remains source-scoped; safety and exposure remain unassessed.
Assessments
CVSS by origin
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:HCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:HCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:HEvidence boundaries
- KEV membership is authoritative for the catalog, not proof of exposure in any environment.
- EPSS is a dated model probability and not an individual-environment prediction.
- Affected or fixed status applies only to the exact cited product and version scope; remaining scope stays source-scoped.
- NVD-carried upstream facts remain derivative; independent corroboration requires a separately authored source.
- Only NVD metrics validated under the generation-bound calculator are Public Priority eligible; direct CVE record metrics remain display-only.
- NVD CVSS source eligibility is closed: NVD-authored, exact record-source, or registered same-CVE container origin; unmapped sources remain display-only.
- Affected-product evidence remains source-scoped; canonical linkage is required before applicability scoring.
- Core replay supports the active and immediately prior generation; retrospective valid-at replay is deferred.
- OSV aggregation and OSV-converted NVD material are not independent corroboration.
- Red Hat facts are vendor assertions for the exact supplied products.
- Nonmembership and not-yet-observed states are not proof of safety.