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

Source: https://junglewise.ai/threats/cve-2026-15714-gnome-libsoup-out-of-bounds-read-in-multipart-boundary-processing  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-07-14. Updated: 2026-07-14  
License: CC BY 4.0 with a link back

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](https://junglewise.ai/threats/technologies/libsoup), [Red Hat Enterprise Linux 10](https://junglewise.ai/threats/technologies/enterprise-linux-10), [Red Hat Enterprise Linux 8](https://junglewise.ai/threats/technologies/enterprise-linux-8), [Red Hat Enterprise Linux 9](https://junglewise.ai/threats/technologies/enterprise-linux-9). Vendors: [Gnome](https://junglewise.ai/threats/vendors/gnome), [Red Hat](https://junglewise.ai/threats/vendors/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

- [https://access.redhat.com/downloads/content/package-browser/](https://access.redhat.com/downloads/content/package-browser/)
- [https://access.redhat.com/security/cve/CVE-2026-15714](https://access.redhat.com/security/cve/CVE-2026-15714)
- [https://bugzilla.redhat.com/show_bug.cgi?id=2499942](https://bugzilla.redhat.com/show_bug.cgi?id=2499942)
- [https://gitlab.gnome.org/GNOME/libsoup/-/work_items/542](https://gitlab.gnome.org/GNOME/libsoup/-/work_items/542)

## Related threats

- [libsoup HTTP request smuggling via undrained Expect: 100-continue body](https://junglewise.ai/threats/cve-2026-103399-a-flaw-was-found-in-soupserver-libsoup-when-an-http-1-x-client)
- [libsoup heap buffer overflow in permessage-deflate WebSocket extension](https://junglewise.ai/threats/cve-2026-102560-a-flaw-was-found-in-libsoup-when-the-permessage-deflate)
- [libsoup heap buffer overflow in WebSocket handling](https://junglewise.ai/threats/cve-2026-102558-a-flaw-was-found-in-libsoup-when-max-incoming-payload-size-is)
- [libsoup out-of-bounds read in data-URI base64 decoding](https://junglewise.ai/threats/cve-2026-102555-a-flaw-was-found-in-libsoup-the-soup-uri-decode-data-uri)
- [libsoup heap corruption in WebSocket message reassembly](https://junglewise.ai/threats/cve-2026-102557-a-flaw-was-found-in-libsoup-when-reassembling-fragmented)