CVE-2026-4271
published 2026-03-17CVE-2026-4271: A flaw was found in libsoup, a library for handling HTTP requests. This vulnerability, known as a Use-After-Free, occurs in the HTTP/2 server implementation. A…
PriorityP345high7.5CVSS 3.1
AVNACLPRNUINSUCNINAH
EPSS
0.86%
58.3th percentile
A flaw was found in libsoup, a library for handling HTTP requests. This vulnerability, known as a Use-After-Free, occurs in the HTTP/2 server implementation. A remote attacker can exploit this by sending specially crafted HTTP/2 requests that cause authentication failures. This can lead to the application attempting to access memory that has already been freed, potentially causing application instability or crashes, resulting in a Denial of Service (DoS).
Affected
9 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| debian | libsoup2.4 | — | — |
| debian | libsoup3 | — | — |
| redhat | enterprise_linux | — | — |
| redhat | enterprise_linux | — | — |
| redhat | enterprise_linux | — | — |
| redhat | enterprise_linux | — | — |
| redhat | enterprise_linux | — | — |
| ubuntu | libsoup2.4 | — | — |
| ubuntu | libsoup3 | — | — |
CVSS provenance
nvdv3.17.5HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
osv7.5HIGH
vendor_ubuntu7.5HIGH
vendor_debian5.3MEDIUM
vendor_redhat5.3MEDIUM
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Ubuntu
libsoup vulnerabilities
vendor_ubuntu·2026-10-21·CVSS 7.5
CVE-2026-85534 [HIGH] libsoup vulnerabilities
Title: libsoup vulnerabilities
Summary: Several security issues were fixed in libsoup.
USN-8890-1 fixed vulnerabilities in libsoup. This update provides the
corresponding updates for libsoup3 on Ubuntu 26.10.
Original advisory details:
It was discovered that libsoup incorrectly handled certain HTTP/2
requests.
A remote attacker could possibly use this issue to cause a denial of
service. This issue only affected Ubuntu 24.04 LTS and Ubuntu 26.04 LTS.
(CVE-2026-4271)
It was discovered that libsoup incorrectly handled certain HTTPS proxy
connections. A remote attacker could possibly use this issue to obtain
sensitive information. This issue only affected Ubuntu 22.04 LTS, Ubuntu
24.04 LTS, and Ubuntu 26.04 LTS. (CVE-2026-5119)
It was discovered that libsoup incorrectly parsed certain ch
Ubuntu
libsoup vulnerabilities
vendor_ubuntu·2026-10-06·CVSS 7.5
CVE-2026-77014 [HIGH] libsoup vulnerabilities
Title: libsoup vulnerabilities
Summary: Several security issues were fixed in libsoup.
It was discovered that libsoup incorrectly handled certain HTTP/2 requests.
A remote attacker could possibly use this issue to cause a denial of
service. This issue only affected Ubuntu 24.04 LTS and Ubuntu 26.04 LTS.
(CVE-2026-4271)
It was discovered that libsoup incorrectly handled certain HTTPS proxy
connections. A remote attacker could possibly use this issue to obtain
sensitive information. This issue only affected Ubuntu 22.04 LTS, Ubuntu
24.04 LTS, and Ubuntu 26.04 LTS. (CVE-2026-5119)
It was discovered that libsoup incorrectly parsed certain chunked HTTP
requests. A remote attacker could possibly use this issue to bypass
security controls. This issue only affected Ubuntu 22.04 LTS, Ubuntu 24.
Red Hat
libsoup: libsoup: Denial of Service via Use-After-Free in HTTP/2 server
vendor_redhat·2026-03-16·CVSS 5.3
CVE-2026-4271 [MEDIUM] CWE-416 libsoup: libsoup: Denial of Service via Use-After-Free in HTTP/2 server
libsoup: libsoup: Denial of Service via Use-After-Free in HTTP/2 server
A flaw was found in libsoup, a library for handling HTTP requests. This vulnerability, known as a Use-After-Free, occurs in the HTTP/2 server implementation. A remote attacker can exploit this by sending specially crafted HTTP/2 requests that cause authentication failures. This can lead to the application attempting to access memory that has already been freed, potentially causing application instability or crashes, resulting in a Denial of Service (DoS).
A flaw was found in libsoup, a library for handling HTTP requests. This vulnerability, known as a Use-After-Free, occurs in the HTTP/2 server implementation. A remote attacker can exploit this by sending specially crafted HTTP/2 requests that cause authentication fa
Debian
CVE-2026-4271: libsoup2.4 - A flaw was found in libsoup, a library for handling HTTP requests. This vulnerab...
vendor_debian·2026·CVSS 5.3
CVE-2026-4271 [MEDIUM] CVE-2026-4271: libsoup2.4 - A flaw was found in libsoup, a library for handling HTTP requests. This vulnerab...
A flaw was found in libsoup, a library for handling HTTP requests. This vulnerability, known as a Use-After-Free, occurs in the HTTP/2 server implementation. A remote attacker can exploit this by sending specially crafted HTTP/2 requests that cause authentication failures. This can lead to the application attempting to access memory that has already been freed, potentially causing application instability or crashes, resulting in a Denial of Service (DoS).
Scope: local
bookworm: open
bullseye: open
trixie: open
OSV
CVE-2026-4271: A flaw was found in libsoup, a library for handling HTTP requests
osv·2026-03-17·CVSS 7.5
CVE-2026-4271 [HIGH] CVE-2026-4271: A flaw was found in libsoup, a library for handling HTTP requests
A flaw was found in libsoup, a library for handling HTTP requests. This vulnerability, known as a Use-After-Free, occurs in the HTTP/2 server implementation. A remote attacker can exploit this by sending specially crafted HTTP/2 requests that cause authentication failures. This can lead to the application attempting to access memory that has already been freed, potentially causing application instability or crashes, resulting in a Denial of Service (DoS).
GHSA
GHSA-xxmc-fm3p-q3x8: A flaw was found in libsoup, a library for handling HTTP requests
ghsa_unreviewed·2026-03-17
CVE-2026-4271 [MEDIUM] CWE-416 GHSA-xxmc-fm3p-q3x8: A flaw was found in libsoup, a library for handling HTTP requests
A flaw was found in libsoup, a library for handling HTTP requests. This vulnerability, known as a Use-After-Free, occurs in the HTTP/2 server implementation. A remote attacker can exploit this by sending specially crafted HTTP/2 requests that cause authentication failures. This can lead to the application attempting to access memory that has already been freed, potentially causing application instability or crashes, resulting in a Denial of Service (DoS).
No detection rules found.
No public exploits indexed.
Bugzilla
CVE-2026-46248 kernel: wifi: ath12k: clear stale link mapping of ahvif->links_map
bugzilla·2026-06-03
CVE-2026-46248 [LOW] CVE-2026-46248 kernel: wifi: ath12k: clear stale link mapping of ahvif->links_map
CVE-2026-46248 kernel: wifi: ath12k: clear stale link mapping of ahvif->links_map
In the Linux kernel, the following vulnerability has been resolved:
wifi: ath12k: clear stale link mapping of ahvif->links_map
When an arvif is initialized in non-AP STA mode but MLO connection
preparation fails before the arvif is created
(arvif->is_created remains false), the error path attempts to delete all
links. However, link deletion only executes when arvif->is_created is true.
As a result, ahvif retains a stale entry of arvif that is initialized but
not created.
When a new arvif is initialized with the same link id, this stale mapping
triggers the following WARN_ON.
WARNING: drivers/net/wireless/ath/ath12k/mac.c:4271 at ath12k_mac_op_change_vif_links+0x140/0x180 [ath12k], CPU#3: wpa_supplicant/2
Bugzilla
CVE-2026-48685 fastnetmon: out-of-bounds memory access due to incorrect parsing of BGP path attributes
bugzilla·2026-05-26·CVSS 6.5
CVE-2026-48685 [MEDIUM] CVE-2026-48685 fastnetmon: out-of-bounds memory access due to incorrect parsing of BGP path attributes
CVE-2026-48685 fastnetmon: out-of-bounds memory access due to incorrect parsing of BGP path attributes
FastNetMon Community Edition through 1.2.9 has out-of-bounds memory access because it incorrectly parses BGP path attributes with the extended length flag set. In src/bgp_protocol.hpp, the parse_raw_bgp_attribute() function correctly identifies when extended_length_bit is set and sets length_of_length_field to 2, but then reads only a single byte for the attribute value length (attribute_value_length = value[2] at line 173). Per RFC 4271 Section 4.3, when the Extended Length bit is set, the Attribute Length field is two octets and the value should be read as a 16-bit big-endian integer from value[2] and value[3]. As a result, any attribute longer than 255 bytes has its length silently tr
Bugzilla
CVE-2026-4271 libsoup: libsoup: Denial of Service via Use-After-Free in HTTP/2 server [fedora-all]
bugzilla·2026-03-16·CVSS 7.5
CVE-2026-4271 [HIGH] CVE-2026-4271 libsoup: libsoup: Denial of Service via Use-After-Free in HTTP/2 server [fedora-all]
CVE-2026-4271 libsoup: libsoup: Denial of Service via Use-After-Free in HTTP/2 server [fedora-all]
Disclaimer: Community trackers are created by Red Hat Product Security team on a best effort basis. Package maintainers are required to ascertain if the flaw indeed affects their package, before starting the update process.
Discussion:
This bug appears to have been reported against 'rawhide' during the Fedora Linux 45 development cycle.
Changing version to 45.
Bugzilla
CVE-2026-4271 mingw-libsoup: libsoup: Denial of Service via Use-After-Free in HTTP/2 server [fedora-all]
bugzilla·2026-03-16·CVSS 7.5
CVE-2026-4271 [HIGH] CVE-2026-4271 mingw-libsoup: libsoup: Denial of Service via Use-After-Free in HTTP/2 server [fedora-all]
CVE-2026-4271 mingw-libsoup: libsoup: Denial of Service via Use-After-Free in HTTP/2 server [fedora-all]
Disclaimer: Community trackers are created by Red Hat Product Security team on a best effort basis. Package maintainers are required to ascertain if the flaw indeed affects their package, before starting the update process.
Bugzilla
CVE-2026-4271 libsoup: libsoup: Denial of Service via Use-After-Free in HTTP/2 server
bugzilla·2026-03-16·CVSS 7.5
CVE-2026-4271 [HIGH] CVE-2026-4271 libsoup: libsoup: Denial of Service via Use-After-Free in HTTP/2 server
CVE-2026-4271 libsoup: libsoup: Denial of Service via Use-After-Free in HTTP/2 server
Use-After-Free vulnerability in the HTTP/2 server implementation of the libsoup HTTP library. The issue occurs in the on_frame_recv_callback() function when processing HTTP/2 frames. During header handling, the function increments an internal callback counter and emits signals such as soup_server_message_got_headers(). If a user-defined signal handler disconnects the client connection during this callback (for example due to authentication failure), the associated SoupServerMessageIOHTTP2 object may be destroyed and freed while still referenced by the callback. When execution returns to the callback, it continues to access the freed io object and attempts to update internal state, resulting in a heap use
Bugzilla
CVE-2026-4271 libsoup3: libsoup: Denial of Service via Use-After-Free in HTTP/2 server [fedora-all]
bugzilla·2026-03-16·CVSS 7.5
CVE-2026-4271 [HIGH] CVE-2026-4271 libsoup3: libsoup: Denial of Service via Use-After-Free in HTTP/2 server [fedora-all]
CVE-2026-4271 libsoup3: libsoup: Denial of Service via Use-After-Free in HTTP/2 server [fedora-all]
Disclaimer: Community trackers are created by Red Hat Product Security team on a best effort basis. Package maintainers are required to ascertain if the flaw indeed affects their package, before starting the update process.
Discussion:
FEDORA-2026-c8cfd2f2f9 (libsoup3-3.6.6-9.fc44) has been submitted as an update to Fedora 44.
https://bodhi.fedoraproject.org/updates/FEDORA-2026-c8cfd2f2f9
---
FEDORA-2026-c8cfd2f2f9 has been pushed to the Fedora 44 testing repository.
Soon you'll be able to install the update with the following command:
`sudo dnf upgrade --enablerepo=updates-testing --refresh --advisory=FEDORA-2026-c8cfd2f2f9`
You can provide feedback for this update here: https://bodhi.
Wiz
CVE-2026-4271 Impact, Exploitability, and Mitigation Steps | Wiz
blogs_wiz·CVSS 5.3
CVE-2026-4271 [MEDIUM] CVE-2026-4271 Impact, Exploitability, and Mitigation Steps | Wiz
## CVE-2026-4271 :
Linux Debian vulnerability analysis and mitigation
A flaw was found in libsoup, a library for handling HTTP requests. This vulnerability, known as a Use-After-Free, occurs in the HTTP/2 server implementation. A remote attacker can exploit this by sending specially crafted HTTP/2 requests that cause authentication failures. This can lead to the application attempting to access memory that has already been freed, potentially causing application instability or crashes, resulting in a Denial of Service (DoS).
Source : NVD
## 7.5
Score
Published March 17, 2026
Severity HIGH
CNA Score 5.3
Affected Technologies
Linux Debian
Linux Red Hat
Has Public Exploit Yes
Has CISA KEV Exploit No
CISA KEV Release Date N/A
CISA KEV Due Date N/A
Exploitation Probability Perc
https://access.redhat.com/errata/RHSA-2026:15968https://access.redhat.com/errata/RHSA-2026:17482https://access.redhat.com/errata/RHSA-2026:19143https://access.redhat.com/security/cve/CVE-2026-4271https://bugzilla.redhat.com/show_bug.cgi?id=2448044https://gitlab.gnome.org/GNOME/libsoup/-/issues/496https://gitlab.gnome.org/GNOME/libsoup/-/issues/496
2026-03-17
Published