RHSA-2026:66210

Vulnerability from csaf_redhat - Published: 2026-09-09 19:47 - Updated: 2026-09-09 20:12
Summary
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: rabbitmq-server4.3: * rabbitmq-server4.3-4.3.5-1.1.hum1 (aarch64, x86_64) * rabbitmq-server4.3-4.3.5-1.1.hum1.src (src) Security Fix(es): rabbitmq-server4.3: * CVE-2026-43971
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.
CVE-2026-43971

A flaw was found in ninenines cowlib. This vulnerability, due to improper encoding or escaping of output, allows an attacker to perform Link header directive smuggling. By manipulating the target URI, 'rel' value, or attribute keys in applications that process Link headers through cowlib, a remote attacker can inject malicious directives. This can force victim browsers to establish out-of-band connections to attacker-controlled servers, potentially leading to information disclosure or bypassing security controls.

4.3 (Medium)
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N
CWE-838 - Inappropriate Encoding for Output Context
Affected products
Product Identifier Version Remediation
Unresolved product id: Red Hat Hardened Images:rabbitmq-server4-3-main@aarch64 —
Vendor Fix fix
Workaround
Unresolved product id: Red Hat Hardened Images:rabbitmq-server4-3-main@src —
Vendor Fix fix
Workaround
Unresolved product id: Red Hat Hardened Images:rabbitmq-server4-3-main@x86_64 —
Vendor Fix fix
Workaround
Threats
Impact Moderate
References
To clipboard 

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        "text": "This update includes the following RPMs:\n\nrabbitmq-server4.3:\n  * rabbitmq-server4.3-4.3.5-1.1.hum1 (aarch64, x86_64)\n  * rabbitmq-server4.3-4.3.5-1.1.hum1.src (src)\n\nSecurity Fix(es):\n\nrabbitmq-server4.3:\n  * CVE-2026-43971",
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        "name": "Inappropriate Encoding for Output Context"
      },
      "discovery_date": "2026-08-18T09:10:57.711245+00:00",
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          "text": "2517738"
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          "text": "A flaw was found in ninenines cowlib. This vulnerability, due to improper encoding or escaping of output, allows an attacker to perform Link header directive smuggling. By manipulating the target URI, \u0027rel\u0027 value, or attribute keys in applications that process Link headers through cowlib, a remote attacker can inject malicious directives. This can force victim browsers to establish out-of-band connections to attacker-controlled servers, potentially leading to information disclosure or bypassing security controls.",
          "title": "Vulnerability description"
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          "text": "cowlib: cowlib: Link header smuggling allows out-of-band connections to attacker-controlled origins",
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        {
          "category": "other",
          "text": "A flaw was found in cowlib, an Erlang library for HTTP parsing and manipulation. Due to improper encoding of output in the cow_link:link/1 function, an attacker can perform Link header directive smuggling by injecting special characters in the target URI, rel value, or attribute keys. Applications that process Link headers through cowlib and pass untrusted input to cow_link:link/1 may force victim browsers to establish out-of-band connections to attacker-controlled servers, potentially leading to information disclosure or bypassing security controls. Red Hat products that bundle cowlib are only affected if they call cow_link:link/1 with untrusted input; actual exploitability in RabbitMQ Server has not been verified.",
          "title": "Statement"
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          ]
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            "attackVector": "NETWORK",
            "availabilityImpact": "NONE",
            "baseScore": 4.3,
            "baseSeverity": "MEDIUM",
            "confidentialityImpact": "NONE",
            "integrityImpact": "LOW",
            "privilegesRequired": "NONE",
            "scope": "UNCHANGED",
            "userInteraction": "REQUIRED",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N",
            "version": "3.1"
          },
          "products": [
            "Red Hat Hardened Images:rabbitmq-server4-3-main@aarch64",
            "Red Hat Hardened Images:rabbitmq-server4-3-main@src",
            "Red Hat Hardened Images:rabbitmq-server4-3-main@x86_64"
          ]
        }
      ],
      "threats": [
        {
          "category": "impact",
          "details": "Moderate"
        }
      ],
      "title": "cowlib: cowlib: Link header smuggling allows out-of-band connections to attacker-controlled origins"
    }
  ]
}



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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

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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.
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  • 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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