Description
A flaw was found in libsoup, an HTTP client/server library. This HTTP Request Smuggling vulnerability arises from non-RFC-compliant parsing in the soup_filter_input_stream_read_line() logic, where libsoup accepts malformed chunk headers, such as lone line feed (LF) characters instead of the required carriage return and line feed (CRLF). A remote attacker can exploit this without authentication or user interaction by sending specially crafted chunked requests. This allows libsoup to parse and process multiple HTTP requests from a single network message, potentially leading to information disclosure.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| 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.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 13 | libsoup3 +1 | No fix yet | — |
| Debian 12 | libsoup3 +1 | No fix yet | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 26.10 | libsoup2.4 | No fix yet | — |
| Ubuntu 25.10 | libsoup3 +1 | No fix yet | — |
| Ubuntu 24.04 LTS | libsoup2.4 | 2.74.3-6ubuntu1.8 | USN-8780-1 |
| Ubuntu 24.04 LTS | libsoup3 | 3.4.4-5ubuntu0.8 | USN-8780-1 |
| Ubuntu 22.04 LTS | libsoup2.4 | 2.74.2-3ubuntu0.8 | USN-8780-1 |
Show 5 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Pro 26.04 LTS | libsoup2.4 | 2.74.3-10.1ubuntu5+esm2 | USN-8780-1 |
| Ubuntu Pro 22.04 LTS | libsoup3 | 3.0.7-0ubuntu1+esm8 | USN-8780-1 |
| Ubuntu Pro 20.04 LTS | libsoup2.4 | 2.70.0-1ubuntu0.5+esm3 | USN-8780-1 |
| Ubuntu Pro 18.04 LTS | libsoup2.4 | 2.62.1-1ubuntu0.4+esm8 | USN-8780-1 |
| Ubuntu Pro 16.04 LTS | libsoup2.4 | 2.52.2-1ubuntu0.3+esm7 | USN-8780-1 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 15 SP7 | libsoup | 3.4.4-150600.3.47.1 | SUSE-SU-2026:2314-1 |
| SLES 15 SP7 | libsoup2 | 2.74.3-150600.4.36.1 | SUSE-SU-2026:2654-1 |
| SLES 15 SP6 | libsoup | 3.4.4-150600.3.47.1 | SUSE-SU-2026:2314-1 |
| SLES 12 SP5 | libsoup | 2.62.2-5.43.1 | SUSE-SU-2026:2702-1 |
Show 6 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES for SAP 15 SP6 | libsoup | 3.4.4-150600.3.47.1 | SUSE-SU-2026:2314-1 |
| SLE Micro 6.1 | libsoup | 3.4.4-slfo.1.1_10.1 | SUSE-SU-2026:22071-1 |
| SLE Micro 6.0 | libsoup | 3.4.2-16.1 | SUSE-SU-2026:22061-1 |
| SLE Micro 5.5 | libsoup2 | 2.74.2-150400.3.37.1 | SUSE-SU-2026:2670-1 |
| SLE Micro 5.4 | libsoup2 | 2.74.2-150400.3.37.1 | SUSE-SU-2026:2670-1 |
| SLE Micro 5.3 | libsoup2 | 2.74.2-150400.3.37.1 | SUSE-SU-2026:2670-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | libsoup2 | 2.74.3-21.1 | openSUSE-SU-2026:10917-1 |
Amazon Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Amazon Linux 2023 | libsoup +2 | 2.72.0-6.amzn2023.0.12 | ALAS2023-2026-1758 |
| Amazon Linux 2023 | libsoup3 +2 | 3.6.6-58.amzn2023 | ALAS2023-2026-1778 |
Azure Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Azure Linux 3 | libsoup | 3.4.4-12 | — |
| Azure Linux 2 (CBL-Mariner) | libsoup | No fix yet | — |
Public exploits
Exploit or proof-of-concept code for this vulnerability is publicly available, which lowers the bar for attackers. Treat it as a reason to patch sooner.
GitHub 1 repository
-
misterdengi/CVE-2026-1801C ★ 0 · Aug 29, 2026
Sources: PoC-in-GitHub, Metasploit Framework, Exploit-DB — updated daily. Only links are listed; no exploit code is hosted here.
Advisories 10
- USN-8780-1 libsoup2.4, libsoup3 vulnerabilities Ubuntu Security Notices (USN) · Sep 18, 2026
- SUSE-SU-2026:2702-1 Security update for libsoup SUSE / openSUSE Security Updates · Jul 1, 2026
- SUSE-SU-2026:2670-1 Security update for libsoup2 SUSE / openSUSE Security Updates · Jun 30, 2026
- SUSE-SU-2026:2654-1 Security update for libsoup2 SUSE / openSUSE Security Updates · Jun 27, 2026
- SUSE-SU-2026:22061-1 Security update for libsoup SUSE / openSUSE Security Updates · Jun 13, 2026
- SUSE-SU-2026:22071-1 Security update for libsoup SUSE / openSUSE Security Updates · Jun 13, 2026
- SUSE-SU-2026:2314-1 Security update for libsoup SUSE / openSUSE Security Updates · Jun 10, 2026
- ALAS2023-2026-1778 Moderate: libsoup3 security update (Amazon Linux 2023) Amazon Linux Security Center (ALAS) · Jun 8, 2026
- openSUSE-SU-2026:10917-1 libsoup-2_4-1-2.74.3-21.1 on GA media SUSE / openSUSE Security Updates · Jun 1, 2026
- ALAS2023-2026-1758 Moderate: libsoup security update (Amazon Linux 2023) Amazon Linux Security Center (ALAS) · May 26, 2026