Summary
The libsoup packages provide an HTTP client and server library for GNOME.
Security Fix(es):
* libsoup: libsoup: Heap buffer overflow from WebSocket Pong signal type confusion (CVE-2026-102556)
* libsoup: libsoup: Heap buffer overflow during WebSocket message reassembly (CVE-2026-102557)
* libsoup: libsoup: Heap buffer overflow during WebSocket receive-buffer growth (CVE-2026-102558)
* libsoup: libsoup: Heap buffer overflow during WebSocket client-frame masking (CVE-2026-102559)
* libsoup: libsoup: Heap buffer overflow during outgoing permessage-deflate buffer growth (CVE-2026-102560)
For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.
Fixed packages 2
| Release | Package | Fixed in |
|---|---|---|
| AlmaLinux · 9 | libsoup | 2.72.0-16.el9_8.8 |
| AlmaLinux · 9 | libsoup-devel | 2.72.0-16.el9_8.8 |
Vulnerabilities 5
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High 8.6
Libsoup: libsoup: heap buffer overflow from websocket pong signal type confusion
A flaw was found in libsoup. When handling an incoming WebSocket Pong frame, SoupWebsocketConnection emitted the ::pong signal with a GByteArray pointer even though the signal is declared to pass a GBytes. Applications connecting a handler that follows the do…
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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 …
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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 …
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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…
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High 8.6
Libsoup: libsoup: heap buffer overflow during outgoing permessage-deflate buffer growth
A flaw was found in libsoup. When the permessage-deflate WebSocket extension compresses a very large outgoing message, truncated size calculations used for GByteArray growth could wrap, causing zlib to write past the allocated buffer and resulting in a heap b…
References
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report
https://access.redhat.com/security/cve/CVE-2026-102556
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report
https://access.redhat.com/security/cve/CVE-2026-102557
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report
https://access.redhat.com/security/cve/CVE-2026-102558
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report
https://access.redhat.com/security/cve/CVE-2026-102559
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report
https://access.redhat.com/security/cve/CVE-2026-102560
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report
https://bugzilla.redhat.com/2543229
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report
https://bugzilla.redhat.com/2543231
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report
https://bugzilla.redhat.com/2543274
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report
https://bugzilla.redhat.com/2543285
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report
https://bugzilla.redhat.com/2543296
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advisory
https://errata.almalinux.org/9/ALSA-2026-83384.html