CVE-2026-58055
nghttp2 nghttpx - HTTP Request/Response Smuggling via Upgrade Request with Content-Length
02 Description
nghttp2 nghttpx - HTTP Request/Response Smuggling via Upgrade Request with Content-Length
03 Exploitation and scoring
- Exploitation
- Assessed, none found. CISA's assessment recorded neither public exploit code nor evidence of exploitation when it was made.
- SSVC decision
- ExploitationnoneCISA recorded no public exploit code and no evidence of exploitation.
- AutomatablenoAt least one step from reconnaissance to exploitation cannot be reliably automated.
- Technical ImpactpartialSuccessful exploitation gives limited control of the vulnerable component.
- EPSS probability
- 0.25% probability of exploitation activity in the next 30 days.
- EPSS percentile
- Equal to or higher than the score of 16.6% of scored records. A rank, not a probability.
- NVD base score
- 6.3 (CVSS v4.0), scored by the NVD independently of the CNA.
- NVD CVSS vector
- CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
- NVD analysis status
- Analyzed. NVD last modified this record on 2026-10-25.
- Red Hat severity
- Moderate. Red Hat's rating for its own products, not a CVSS rating.
Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.
04 Metadata
- Published
- 2026-06-28 01:32Z4 MO AGO
- Last updated
- 2026-06-29 13:51Z4 MO AGO
- Reserved
- 2026-06-28
- Assigning CNA
- VulnCheck
- Record state
- PUBLISHED
- Severity
- Medium (CVSS 6.3)
- CNA CVSS vector
- CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:L/SA:N
- Weaknesses
- CWE-444Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling')Base
- Data version
- 5.2
- Document digest
- 1f281be267402e8339561e9d2cd3867f7e5207d1eb2541affb385e0366c39f44
05 Affected products
06 References
- github.comProof of Concepthttps://github.com/bikini/exploitarium/tree/main/nghttp2-nghttpx-upgrade-queue-poison-poc
- github.comFix commit (master)https://github.com/nghttp2/nghttp2/commit/ab28105c4a0197da24f8bfc414bc116055249e1e
- www.vulncheck.comVulnCheck Advisory: nghttp2 nghttpx - HTTP Request/Response Smuggling via Upgrade Request with Content-Lengthhttps://www.vulncheck.com/advisories/nghttp2-nghttpx-http-request-response-smuggling-via-upgrade-request-with-content-length
07 Fixed in
AlmaLinux 8
- libnghttp2 Fixed in 1.33.0-6.el8_10.3
- libnghttp2-devel Fixed in 1.33.0-6.el8_10.3
- nghttp2 Fixed in 1.33.0-6.el8_10.3
Source: AlmaLinux, AlmaLinux OS. Copyright (c) 2023 AlmaLinux OS. Licensed under MIT License. Received through OSV.dev. Reformatted by exploit.cc.
AlmaLinux 9
- libnghttp2 Fixed in 1.43.0-6.el9_8.2
- libnghttp2-devel Fixed in 1.43.0-6.el9_8.2
- nghttp2 Fixed in 1.43.0-6.el9_8.2
Source: AlmaLinux, AlmaLinux OS. Copyright (c) 2023 AlmaLinux OS. Licensed under MIT License. Received through OSV.dev. Reformatted by exploit.cc.
AlmaLinux 10
- libnghttp2 Fixed in 1.68.0-3.el10_2.2
- libnghttp2-devel Fixed in 1.68.0-3.el10_2.2
- nghttp2 Fixed in 1.68.0-3.el10_2.2
Source: AlmaLinux, AlmaLinux OS. Copyright (c) 2023 AlmaLinux OS. Licensed under MIT License. Received through OSV.dev. Reformatted by exploit.cc.
CloudLinux 8
- libnghttp2 Fixed in 1.33.0-6.el8_10.3
- libnghttp2-devel Fixed in 1.33.0-6.el8_10.3
- nghttp2 Fixed in 1.33.0-6.el8_10.3
Derived from AlmaLinux 8. Partial coverage: only packages taken from AlmaLinux 8 are listed.
Source: CloudLinux errata, CloudLinux Inc. Derived from: AlmaLinux, AlmaLinux OS. Copyright (c) 2023 AlmaLinux OS. Licensed under MIT License. Received through OSV.dev. Reformatted by exploit.cc.
CloudLinux 9
- libnghttp2 Fixed in 1.43.0-6.el9_8.2
- libnghttp2-devel Fixed in 1.43.0-6.el9_8.2
- nghttp2 Fixed in 1.43.0-6.el9_8.2
Derived from AlmaLinux 9. Partial coverage: only packages taken from AlmaLinux 9 are listed.
Source: CloudLinux errata, CloudLinux Inc. Derived from: AlmaLinux, AlmaLinux OS. Copyright (c) 2023 AlmaLinux OS. Licensed under MIT License. Received through OSV.dev. Reformatted by exploit.cc.
CloudLinux 10
- libnghttp2 Fixed in 1.68.0-3.el10_2.2
- libnghttp2-devel Fixed in 1.68.0-3.el10_2.2
- nghttp2 Fixed in 1.68.0-3.el10_2.2
Derived from AlmaLinux 10. Partial coverage: only packages taken from AlmaLinux 10 are listed.
Source: CloudLinux errata, CloudLinux Inc. Derived from: AlmaLinux, AlmaLinux OS. Copyright (c) 2023 AlmaLinux OS. Licensed under MIT License. Received through OSV.dev. Reformatted by exploit.cc.
Debian 12
- nghttp2 No fix yet
Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.
Debian 13
- nghttp2 No fix yet
Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.
Debian 14
- nghttp2 Fixed in 1.70.0-1
Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu 22.04 LTS
- nghttp2 Fixed in 1.43.0-1ubuntu0.4
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu 24.04 LTS
- nghttp2 Fixed in 1.59.0-1ubuntu0.4
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu 25.10
- nghttp2 Fixed in 1.64.0-1.1ubuntu1.2
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu 26.04 LTS
- nghttp2 Fixed in 1.68.0-2ubuntu0.2
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu Pro 16.04 LTS
- nghttp2 No fix yet
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu Pro 18.04 LTS
- nghttp2 No fix yet
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu Pro 20.04 LTS
- nghttp2 No fix yet
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
A release or ecosystem missing from this list has no record here. It may be unaffected or not covered by the source. Source notices and licences.