Summary
Package updates are available for Amazon Linux 2023 that fix the following vulnerabilities: CVE-2026-5119: A flaw was found in libsoup. When establishing HTTPS tunnels through a configured HTTP proxy, sensitive session cookies are transmitted in cleartext within the initial HTTP CONNECT request. A network-positioned attacker or a malicious HTTP proxy can intercept these cookies, leading to potential session hijacking or user impersonation. CVE-2026-2708: libsoup includes an embedded HTTP/1 server. When a server sits behind a proxy / load balancer, it's critical that every hop agrees on how request bodies are framed. In the affected code path, libsoup accepted HTTP/1 requests with ambiguous body framing: multiple Content-Length headers (CL.CL) Transfer-Encoding: chunked together with Content-Length (TE+CL) Different intermediaries pick different framing rules in these cases. If a front-end and back-end disagree, an attacker can desynchronize the connection and "smuggle" an extra request through the chain. Depending on deployment, this can lead to routing/ACL bypass, cache poisoning, or reaching internal-only endpoints. CVE-2026-2436: Denial of Service via use-after-free in SoupServer during TLS handshake CVE-2026-1801: A flaw was found in libsoup, an HTTP client/server library. This HTTP Request Smuggling vulnerability arises from non-RFC-compliant parsing in the soup_filter_input_stream_read_line() logic, where libsoup accepts malformed chunk headers, such as lone line feed (LF) characters instead of the required carriage return and line feed (CRLF). A remote attacker can exploit this without authentication or user interaction by sending specially crafted chunked requests. This allows libsoup to parse and process multiple HTTP requests from a single network message, potentially leading to information disclosure. CVE-2026-1761: A flaw was found in libsoup. This stack-based buffer overflow vulnerability occurs during the parsing of multipart HTTP responses due to an incorrect length calculation. A remote attacker can exploit this by sending a specially crafted multipart HTTP response, which can lead to memory corruption. This issue may result in application crashes or arbitrary code execution in applications that process untrusted server responses, and it does not require authentication or user interaction. CVE-2026-1760: A flaw was found in SoupServer. This HTTP request smuggling vulnerability occurs because SoupServer improperly handles requests that combine Transfer-Encoding: chunked and Connection: keep-alive headers. A remote, unauthenticated client can exploit this by sending specially crafted requests, causing SoupServer to fail to close the connection as required by RFC 9112. This allows the attacker to smuggle additional requests over the persistent connection, leading to unintended request processing and potential denial-of-service (DoS) conditions. CVE-2026-1467: A flaw was found in libsoup, an HTTP client library. This vulnerability, known as CRLF (Carriage Return Line Feed) Injection, occurs when an HTTP proxy is configured and the library improperly handles URL-decoded input used to create the Host header. A remote attacker can exploit this by providing a specially crafted URL containing CRLF sequences, allowing them to inject additional HTTP headers or complete HTTP request bodies. This can lead to unintended or unauthorized HTTP requests being forwarded by the proxy, potentially impacting downstream services. CVE-2026-0716: OOB Read via Integer Overflow on libsoup through libsoup/websocket/soup-websocket-connection.c via process_frame() leads to Undefined Behavior
Fixed packages 5
| Release | Package | Fixed in |
|---|---|---|
| Amazon Linux · 2023 | libsoup3 | 0:3.6.6-58.amzn2023 |
| Amazon Linux · 2023 | libsoup3-debuginfo | 0:3.6.6-58.amzn2023 |
| Amazon Linux · 2023 | libsoup3-debugsource | 0:3.6.6-58.amzn2023 |
| Amazon Linux · 2023 | libsoup3-devel | 0:3.6.6-58.amzn2023 |
| Amazon Linux · 2023 | libsoup3-doc | 0:3.6.6-58.amzn2023 |
Vulnerabilities 8
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High 8.6
Libsoup: stack-based buffer overflow in libsoup multipart response parsingmultipart http response
A flaw was found in libsoup. This stack-based buffer overflow vulnerability occurs during the parsing of multipart HTTP responses due to an incorrect length calculation. A remote attacker can exploit this by sending a specially crafted multipart HTTP response…
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Medium 6.5
Libsoup: libsoup: denial of service via use-after-free in soupserver during tls handshake
A flaw was found in libsoup's SoupServer. A remote attacker could exploit a use-after-free vulnerability where the `soup_server_disconnect()` function frees connection objects prematurely, even if a TLS handshake is still pending. If the handshake completes a…
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Medium 5.9
Libsoup: libsoup: information disclosure via cleartext transmission of cookies during https tunnel establishment
A flaw was found in libsoup. When establishing HTTPS tunnels through a configured HTTP proxy, sensitive session cookies are transmitted in cleartext within the initial HTTP CONNECT request. A network-positioned attacker or a malicious HTTP proxy can intercept…
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Medium 5.8
Libsoup: libsoup: http header injection via specially crafted urls when an http proxy is configured
A flaw was found in libsoup, an HTTP client library. This vulnerability, known as CRLF (Carriage Return Line Feed) Injection, occurs when an HTTP proxy is configured and the library improperly handles URL-decoded input used to create the Host header. A remote…
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Medium 5.3
Libsoup: soupserver: denial of service via http request smuggling
A flaw was found in SoupServer. This HTTP request smuggling vulnerability occurs because SoupServer improperly handles requests that combine Transfer-Encoding: chunked and Connection: keep-alive headers. A remote, unauthenticated client can exploit this by se…
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Medium 5.3CVE-2026-1801 Public exploit
Libsoup: libsoup: http request smuggling via malformed chunk headers
A flaw was found in libsoup, an HTTP client/server library. This HTTP Request Smuggling vulnerability arises from non-RFC-compliant parsing in the soup_filter_input_stream_read_line() logic, where libsoup accepts malformed chunk headers, such as lone line fee…
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Medium 4.8
Libsoup: out-of-bounds read in libsoup websocket frame processing
A flaw was found in libsoup’s WebSocket frame processing when handling incoming messages. If a non-default configuration is used where the maximum incoming payload size is unset, the library may read memory outside the intended bounds. This can cause unintend…
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Low 3.7
Libsoup: libsoup: http request smuggling via duplicate content-length headers
A request smuggling vulnerability exists in libsoup's HTTP/1 header parsing logic. The soup_message_headers_append_common() function in libsoup/soup-message-headers.c unconditionally appends each header value without validating for duplicate or conflicting Co…
References
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web
https://alas.aws.amazon.com/cve/html/CVE-2026-0716.html
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web
https://alas.aws.amazon.com/cve/html/CVE-2026-1467.html
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web
https://alas.aws.amazon.com/cve/html/CVE-2026-1760.html
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web
https://alas.aws.amazon.com/cve/html/CVE-2026-1761.html
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web
https://alas.aws.amazon.com/cve/html/CVE-2026-1801.html
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web
https://alas.aws.amazon.com/cve/html/CVE-2026-2436.html
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web
https://alas.aws.amazon.com/cve/html/CVE-2026-2708.html
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web
https://alas.aws.amazon.com/cve/html/CVE-2026-5119.html