RHSA-2026:35454
Vulnerability from csaf_redhat - Published: 2026-07-03 13:49 - Updated: 2026-07-21 06:34Summary
Red Hat Security Advisory: Red Hat Hardened Images RPMs Security Update
Severity
Moderate
Notes
Topic: An update for Red Hat Hardened Images RPMs is now available.
Details: This update includes the following RPMs:
nghttp2:
* libnghttp2-1.69.0-3.1.hum1 (aarch64, x86_64)
* libnghttp2-devel-1.69.0-3.1.hum1 (aarch64, x86_64)
* mingw32-libnghttp2-1.69.0-3.1.hum1 (aarch64, x86_64)
* mingw64-libnghttp2-1.69.0-3.1.hum1 (aarch64, x86_64)
* nghttp2-1.69.0-3.1.hum1 (aarch64, x86_64)
* nghttp2-1.69.0-3.1.hum1.src (src)
Security Fix(es):
nghttp2:
* CVE-2026-58055
Terms of Use: This content is licensed under the Creative Commons Attribution 4.0 International License (https://creativecommons.org/licenses/by/4.0/). If you distribute this content, or a modified version of it, you must provide attribution to Red Hat Inc. and provide a link to the original.
A flaw in nghttp2's nghttpx proxy allows a remote attacker to perform HTTP request smuggling and cross-client response-queue poisoning. This occurs because the proxy ambiguously forwards HTTP/1.1 Upgrade requests that contain a Content-Length header to reusable keep-alive backend connections.
5.4 (Medium)
Affected products
Fixed
3 products
| Product | Identifier | Version | Remediation |
|---|---|---|---|
| Unresolved product id: Red Hat Hardened Images:nghttp2-main@aarch64 | — |
Vendor Fix
fix
Workaround
|
|
| Unresolved product id: Red Hat Hardened Images:nghttp2-main@src | — |
Vendor Fix
fix
Workaround
|
|
| Unresolved product id: Red Hat Hardened Images:nghttp2-main@x86_64 | — |
Vendor Fix
fix
Workaround
|
Threats
Impact
Moderate
References
12 references
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"text": "This update includes the following RPMs:\n\nnghttp2:\n * libnghttp2-1.69.0-3.1.hum1 (aarch64, x86_64)\n * libnghttp2-devel-1.69.0-3.1.hum1 (aarch64, x86_64)\n * mingw32-libnghttp2-1.69.0-3.1.hum1 (aarch64, x86_64)\n * mingw64-libnghttp2-1.69.0-3.1.hum1 (aarch64, x86_64)\n * nghttp2-1.69.0-3.1.hum1 (aarch64, x86_64)\n * nghttp2-1.69.0-3.1.hum1.src (src)\n\nSecurity Fix(es):\n\nnghttp2:\n * CVE-2026-58055",
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"vulnerabilities": [
{
"cve": "CVE-2026-58055",
"cwe": {
"id": "CWE-444",
"name": "Inconsistent Interpretation of HTTP Requests (\u0027HTTP Request/Response Smuggling\u0027)"
},
"discovery_date": "2026-06-28T03:01:22.756250+00:00",
"ids": [
{
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"text": "2493954"
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"notes": [
{
"category": "description",
"text": "A flaw in nghttp2\u0027s nghttpx proxy allows a remote attacker to perform HTTP request smuggling and cross-client response-queue poisoning. This occurs because the proxy ambiguously forwards HTTP/1.1 Upgrade requests that contain a Content-Length header to reusable keep-alive backend connections.",
"title": "Vulnerability description"
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"text": "nghttp2: nghttp2: HTTP Request/Response Smuggling and Response-Queue Poisoning via ambiguous HTTP/1.1 Upgrade requests",
"title": "Vulnerability summary"
},
{
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"text": "A flaw in nghttp2\u0027s nghttpx proxy allows remote HTTP request smuggling and cross-client response poisoning by forwarding malformed HTTP/1.1 Upgrade requests containing a Content-Length body. This is rated Moderate because successful exploitation requires high attack complexity on the backend server.",
"title": "Statement"
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"Red Hat Hardened Images:nghttp2-main@src",
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{
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"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-58055"
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{
"category": "external",
"summary": "https://github.com/bikini/exploitarium/tree/main/nghttp2-nghttpx-upgrade-queue-poison-poc",
"url": "https://github.com/bikini/exploitarium/tree/main/nghttp2-nghttpx-upgrade-queue-poison-poc"
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{
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"summary": "https://github.com/nghttp2/nghttp2/commit/ab28105c4a0197da24f8bfc414bc116055249e1e",
"url": "https://github.com/nghttp2/nghttp2/commit/ab28105c4a0197da24f8bfc414bc116055249e1e"
},
{
"category": "external",
"summary": "https://www.vulncheck.com/advisories/nghttp2-nghttpx-http-request-response-smuggling-via-upgrade-request-with-content-length",
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"release_date": "2026-06-28T01:32:57.163000+00:00",
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"date": "2026-07-03T13:49:44+00:00",
"details": "For details on how to apply this update, which includes the changes described in this advisory, refer to:\nhttps://images.redhat.com/",
"product_ids": [
"Red Hat Hardened Images:nghttp2-main@aarch64",
"Red Hat Hardened Images:nghttp2-main@src",
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{
"category": "workaround",
"details": "Configure your WAF or load balancer to drop incoming HTTP/1.1 requests that contain both Upgrade and Content-Length headers. This blocks the malformed traffic at the edge before it can reach the vulnerable proxy without impacting legitimate users.",
"product_ids": [
"Red Hat Hardened Images:nghttp2-main@aarch64",
"Red Hat Hardened Images:nghttp2-main@src",
"Red Hat Hardened Images:nghttp2-main@x86_64"
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"scores": [
{
"cvss_v3": {
"attackComplexity": "HIGH",
"attackVector": "NETWORK",
"availabilityImpact": "NONE",
"baseScore": 5.4,
"baseSeverity": "MEDIUM",
"confidentialityImpact": "LOW",
"integrityImpact": "LOW",
"privilegesRequired": "NONE",
"scope": "CHANGED",
"userInteraction": "NONE",
"vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:L/A:N",
"version": "3.1"
},
"products": [
"Red Hat Hardened Images:nghttp2-main@aarch64",
"Red Hat Hardened Images:nghttp2-main@src",
"Red Hat Hardened Images:nghttp2-main@x86_64"
]
}
],
"threats": [
{
"category": "impact",
"details": "Moderate"
}
],
"title": "nghttp2: nghttp2: HTTP Request/Response Smuggling and Response-Queue Poisoning via ambiguous HTTP/1.1 Upgrade requests"
}
]
}
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Experimental. This forecast is provided for visualization only and may change without notice. Do not use it for operational decisions.
Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
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The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the
vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base
model, served locally by ML-Gateway.
They have not been verified by an analyst and are provided for guidance only.
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