CVE-2026-15714: GNOME libsoup out-of-bounds read in multipart boundary processing

CVE-2026-15714 · Severity: medium · CVSS 6.5 · Published 2026-07-14

libsoup, a widely used networking library for GNOME and Linux applications, contains a flaw in how it handles multi-part web responses. A malicious server can send a specially crafted response that causes an application using this library to crash or potentially leak small fragments of its memory. This could lead to a service outage for affected software or the exposure of sensitive internal data.

Technologies: Gnome Libsoup, Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 8, Red Hat Enterprise Linux 9. Vendors: Gnome, Red Hat.

Quick answers

Is CVE-2026-15714 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2026-15714 being exploited in the wild.
How severe is CVE-2026-15714?
Medium severity, with a CVSS score of 6.5, published 14 July 2026.
Which products and versions are affected?
Gnome Libsoup 3.7.0; Red Hat Enterprise Linux 10 affected; Red Hat Enterprise Linux 8 affected; Red Hat Enterprise Linux 9 affected.
Is there a fix for CVE-2026-15714?
No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.
How is CVE-2026-15714 attacked?
It is attacked over the network, in a software library.
Am I affected by CVE-2026-15714?
Check whether you run Gnome Libsoup, Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 8 or one of the others listed at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

Technical details

An out-of-bounds read exists in libsoup's `soup_multipart_input_stream_read_headers()` function within `soup-multipart-input-stream.c`. The vulnerability is caused by a lack of length validation when performing a `strncmp()` comparison between a partially-buffered line (`meta_buf`) and an attacker-controlled multipart boundary string. A remote, unauthenticated attacker can provide an oversized boundary parameter in a `Content-Type` header and send the response body in specific chunks to force the library to read past the allocated buffer. This can result in a heap-buffer-overflow, leading to an application crash (DoS) or potential information disclosure of adjacent memory contents.

Affected products

  • GNOME libsoup 3.7.0
  • Red Hat Red Hat Enterprise Linux 8 affected
  • Red Hat Red Hat Enterprise Linux 9 affected
  • Red Hat Red Hat Enterprise Linux 10 affected

Timeline

  • 2026-02-12: disclosed: Reported via YesWeHack to GNOME libsoup maintainers
  • 2026-07-14: advisory: CVE published and Red Hat advisory issued

References

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