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OpenAdvisories
Medium · 6.5 CVE-2026-66337 EUVD-2026-48753GHSA-ww4c-c3rv-f96h

Libsoup: libsoup: heap buffer over-read via integer underflow in soup_filter_input_stream_read_until()

Published Jul 24, 2026 · Updated Nov 5, 2026 · Assigned by redhat

Description

A flaw was found in libsoup. An unsigned integer underflow in the soup_filter_input_stream_read_until() function causes a heap buffer over-read when parsing multipart HTTP responses. A malicious HTTP server can exploit this by sending a crafted multipart response, potentially causing the client application to crash or disclose sensitive heap memory.

Affected products

VendorProductAffectedFixed
Red Hat Red Hat Enterprise Linux 10 — —
Red Hat Red Hat Enterprise Linux 6 — —
Red Hat Red Hat Enterprise Linux 7 — —
Red Hat Red Hat Enterprise Linux 8 — —
Red Hat Red Hat Enterprise Linux 9 — —

Fixed in Linux distributions

Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.

ReleasePackageFixed inAdvisory
Debian 13 libsoup3 +1 No fix yet —
Debian 12 libsoup3 +1 No fix yet —
ReleasePackageFixed inAdvisory
Ubuntu 26.10 libsoup3 +1 No fix yet —
Ubuntu 26.04 LTS libsoup3 No fix yet —
Ubuntu 24.04 LTS libsoup3 +1 No fix yet —
Ubuntu 22.04 LTS libsoup2.4 No fix yet —
Show 5 more (older releases, extended support, other products)
ReleasePackageFixed inAdvisory
Ubuntu Pro 26.04 LTS libsoup2.4 No fix yet —
Ubuntu Pro 22.04 LTS libsoup3 No fix yet —
Ubuntu Pro 20.04 LTS libsoup2.4 No fix yet —
Ubuntu Pro 18.04 LTS libsoup2.4 No fix yet —
Ubuntu Pro 16.04 LTS libsoup2.4 No fix yet —
ReleasePackageFixed inAdvisory
openSUSE Tumbleweed libsoup 3.8.1-1.1 openSUSE-SU-2026:12365-1

Amazon Linux

ReleasePackageFixed inAdvisory
Amazon Linux 2023 libsoup +2 2.72.0-6.amzn2023.0.16 ALAS2023-2026-3212
Amazon Linux 2023 libsoup3 +2 3.7.3-1.amzn2023 ALAS2023-2026-3421, ALAS2023-2026-3240
Amazon Linux 2 libsoup +1 2.56.0-6.amzn2.0.9 ALAS2-2026-3970

Azure Linux

ReleasePackageFixed inAdvisory
Azure Linux 3 libsoup No fix yet —

Advisories 5

References