Summary
Package updates are available for Amazon Linux 2 that fix the following vulnerabilities: CVE-2026-15714: An out-of-bounds read vulnerability was found in libsoup's multipart processing subsystem. The flaw exists in the soup_multipart_input_stream_read_headers() function inside soup-multipart-input-stream.c, which does not adequately restrict or validate the size of incoming multipart boundary strings. When processing a crafted HTTP response containing a malformed or oversized boundary parameter, the internal stream reader reads past the allocated buffer bounds. A remote, unauthenticated attacker can exploit this behavior to cause a service denial (DoS) through application failure or potentially read fragments of unauthorized memory metadata. CVE-2026-103399: A flaw was found in SoupServer (libsoup). When an HTTP/1.x client sends a request with Expect: 100-continue and a request body, and SoupServer returns an early final (non-1xx) response before the body is read, the server neither drains the declared body bytes nor closes the connection. On a keep-alive connection, those leftover bytes are interpreted as a subsequent HTTP request. A remote, unauthenticated attacker can place a complete HTTP request in the body and cause SoupServer to process that smuggled request, leading to unintended request handling. CVE-2026-102559: A flaw was found in libsoup. When constructing a masked WebSocket client frame for a very large outgoing payload, size values passed to GByteArray allocation APIs could be truncated while the masking routine still used the full length, causing a heap buffer overflow. CVE-2026-102558: A flaw was found in libsoup. When max-incoming-payload-size is unlimited (0), SoupWebsocketConnection could grow its incoming GByteArray based on an attacker-controlled frame length until the length wrapped, causing a heap buffer overflow while reading frame data. CVE-2026-102557: A flaw was found in libsoup. When reassembling fragmented WebSocket messages into a GByteArray, libsoup did not adequately cap total message size against the limits of the underlying buffer type. A remote peer could send fragments that caused size truncation while the implementation still used the full length, leading to heap corruption or a crash.
Fixed packages 3
| Release | Package | Fixed in |
|---|---|---|
| Amazon Linux · 2 | libsoup | 0:2.56.0-6.amzn2.0.10 |
| Amazon Linux · 2 | libsoup-debuginfo | 0:2.56.0-6.amzn2.0.10 |
| Amazon Linux · 2 | libsoup-devel | 0:2.56.0-6.amzn2.0.10 |
Vulnerabilities 5
-
High 8.6
Libsoup: libsoup: heap buffer overflow during websocket message reassembly
A flaw was found in libsoup. When reassembling fragmented WebSocket messages into a GByteArray, libsoup did not adequately cap total message size against the limits of the underlying buffer type. A remote peer could send fragments that caused size truncation …
-
High 8.6
Libsoup: libsoup: heap buffer overflow during websocket receive-buffer growth
A flaw was found in libsoup. When max-incoming-payload-size is unlimited (0), SoupWebsocketConnection could grow its incoming GByteArray based on an attacker-controlled frame length until the length wrapped, causing a heap buffer overflow while reading frame …
-
High 8.6
Libsoup: libsoup: heap buffer overflow during websocket client-frame masking
A flaw was found in libsoup. When constructing a masked WebSocket client frame for a very large outgoing payload, size values passed to GByteArray allocation APIs could be truncated while the masking routine still used the full length, causing a heap buffer o…
-
Medium 6.5
Libsoup: soupmultipartinputstream: libsoup: out-of-bounds read in soup_multipart_input_stream_read_headers via an oversized multipart boundary string
An out-of-bounds read vulnerability was found in libsoup's multipart processing subsystem. The flaw exists in the soup_multipart_input_stream_read_headers() function inside soup-multipart-input-stream.c, which does not adequately restrict or validate the size…
-
Medium 5.3
Libsoup: soupserver: http/1 request smuggling via undrained expect: 100-continue body
A flaw was found in SoupServer (libsoup). When an HTTP/1.x client sends a request with Expect: 100-continue and a request body, and SoupServer returns an early final (non-1xx) response before the body is read, the server neither drains the declared body bytes…
References
-
web
https://alas.aws.amazon.com/cve/html/CVE-2026-102557.html
-
web
https://alas.aws.amazon.com/cve/html/CVE-2026-102558.html
-
web
https://alas.aws.amazon.com/cve/html/CVE-2026-102559.html
-
web
https://alas.aws.amazon.com/cve/html/CVE-2026-103399.html
-
web
https://alas.aws.amazon.com/cve/html/CVE-2026-15714.html