CVE-2026-58055

Aliases:MGASA-2026-0309SUSE-SU-2026:22707-1SUSE-SU-2026:22893-1SUSE-SU-2026:3153-1SUSE-SU-2026:3154-1RHSA-2026:35454RHSA-2026:52414DEBIAN-CVE-2026-58055RHSA-2026:54650RHSA-2026:54662RHSA-2026:55804CGA-43r8-f2xj-r388CGA-7g67-8qrj-cr3qCGA-7mv6-22fj-jvj9CGA-8pjw-3mvg-2x6mCGA-gch4-9wcf-mxwrCGA-mrwp-fgwh-65q5CGA-p7p7-4fgv-w69rCGA-x2jp-wcw6-9pcmSUSE-SU-2026:4029-1
Advisory lineage Upstream: 0 Downstream: 9
Analyzed
Published: 28 Jun 2026, 01:32
Last modified:29 Jun 2026, 13:51

Vulnerability Summary

Overall Risk (default)
medium
35/100
CVSS Score
6.3 MEDIUM
v4.0 (cve.org)
EPSS Score
0.25% LOW
0% probability 0.00%
KEV
Not listed
Ransomware
No reports
Public exploits
1 found
Dark Web
Not detected

Timeline

28 Jun 2026, 01:32
Published
Vulnerability first disclosed
29 Jun 2026, 13:51
Last Modified
Vulnerability information updated

Description

nghttp2's nghttpx proxy through 1.69.0 forwards an HTTP/1.1 Upgrade request that also carries a Content-Length header and body onto reusable keep-alive backend connections, re-adding the Upgrade and Connection headers while passing Content-Length verbatim. A backend that resolves the resulting ambiguous message in the attacker's favor enables HTTP request/response smuggling and cross-client response-queue poisoning.

CVSS Metrics

  • v4.0•MEDIUM•Score: 6.3CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:L/SA:N
  • v4.0•MEDIUM•Score: 6.3CVSS: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
  • v3.1•MEDIUM•Score: 5.4CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:L/A:N

EPSS Trends

Current EPSS score: 0.25%• Percentile: 17%

Techniques & Countermeasures

  • CWE-444•Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling')

    The product acts as an intermediary HTTP agent (such as a proxy or firewall) in the data flow between two entities such as a client and server, but it does not interpret malformed HTTP requests or responses in ways that are consistent with how the messages will be processed by those entities that are at the ultimate destination.

Affected Systems

  • chainguard•libnghttp2-14

    < 1.70.0-r0

  • chainguard•nghttp2

    < 1.70.0-r0

  • chainguard•nghttp2-dev

    < 1.70.0-r0

  • chainguard•nghttp2-doc

    < 1.70.0-r0

  • wolfi•libnghttp2-14

    < 1.70.0-r0

  • wolfi•nghttp2

    < 1.70.0-r0

  • wolfi•nghttp2-dev

    < 1.70.0-r0

  • wolfi•nghttp2-doc

    < 1.70.0-r0

  • debian•nghttp2

    all | all | all | all | < 1.70.0-1

  • mageia•nghttp2

    < 1.68.1-2.1.mga10

  • mageia•nghttp2

    < 1.61.0-1.2.mga9

  • nghttp2•nghttp2

    ≤ 1.69.0

  • redhat•libnghttp2

    < 0:1.69.0-3.1.hum1 | < 0:1.69.0-5.hum1 | < 0:1.68.0-3.el10_2.2 | < 0:1.43.0-6.el9_8.2 | < 0:1.33.0-6.el8_10.3

  • redhat•libnghttp2-debuginfo

    < 0:1.68.0-3.el10_2.2 | < 0:1.43.0-6.el9_8.2 | < 0:1.43.0-6.el9_8.2 | < 0:1.33.0-6.el8_10.3 | < 0:1.33.0-6.el8_10.3

  • redhat•libnghttp2-devel

    < 0:1.68.0-3.el10_2.2 | < 0:1.43.0-6.el9_8.2 | < 0:1.33.0-6.el8_10.3

  • redhat•nghttp2

    < 0:1.69.0-3.1.hum1 | < 0:1.69.0-5.hum1 | < 0:1.68.0-3.el10_2.2 | < 0:1.43.0-6.el9_8.2 | < 0:1.43.0-6.el9_8.2 | < 0:1.33.0-6.el8_10.3 | < 0:1.33.0-6.el8_10.3

  • redhat•nghttp2-debuginfo

    < 0:1.68.0-3.el10_2.2 | < 0:1.43.0-6.el9_8.2 | < 0:1.43.0-6.el9_8.2 | < 0:1.33.0-6.el8_10.3 | < 0:1.33.0-6.el8_10.3

  • redhat•nghttp2-debugsource

    < 0:1.68.0-3.el10_2.2 | < 0:1.43.0-6.el9_8.2 | < 0:1.43.0-6.el9_8.2 | < 0:1.33.0-6.el8_10.3 | < 0:1.33.0-6.el8_10.3

  • suse•nghttp2&distro=SUSE Linux Enterprise Module for Basesystem 15 SP7

    < 1.40.0-150600.25.8.1 | < 1.64.0-150700.3.6.1

  • suse•nghttp2&distro=SUSE Linux Enterprise Server LTSS Extended Security 12 SP5

    < 1.39.2-3.26.1

  • suse•nghttp2&distro=SUSE Linux Micro 6.0

    < 1.52.0-7.1

  • suse•nghttp2&distro=SUSE Linux Micro 6.1

    < 1.52.0-slfo.1.1_3.1

References (32)