Description
A flaw was found in libsoup. A remote attacker could exploit an unsigned to signed conversion error in the `soup_body_input_stream_read_chunked()` function by sending a malicious HTTP request. This vulnerability occurs when libsoup operates behind a non-libsoup proxy server or as a proxy in front of a non-libsoup backend server. Successful exploitation can allow an attacker to bypass security controls, poison web caches, or gain unauthorized access.
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 26.10 | libsoup3 | 3.6.6-1ubuntu3 | USN-8890-2 |
| Ubuntu 26.04 LTS | libsoup2.4 | No fix yet | — |
| Ubuntu 26.04 LTS | libsoup3 | 3.6.6-1ubuntu0.1 | USN-8890-1 |
| Ubuntu 25.10 | libsoup3 +1 | No fix yet | — |
| Ubuntu 24.04 LTS | libsoup2.4 | 2.74.3-6ubuntu1.9 | USN-8890-1 |
| Ubuntu 24.04 LTS | libsoup3 | 3.4.4-5ubuntu0.9 | USN-8890-1 |
| Ubuntu 22.04 LTS | libsoup2.4 | 2.74.2-3ubuntu0.9 | USN-8890-1 |
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+esm3 | USN-8890-1 |
| Ubuntu Pro 22.04 LTS | libsoup3 | 3.0.7-0ubuntu1+esm9 | USN-8890-1 |
| Ubuntu Pro 20.04 LTS | libsoup2.4 | 2.70.0-1ubuntu0.5+esm4 | USN-8890-1 |
| Ubuntu Pro 18.04 LTS | libsoup2.4 | 2.62.1-1ubuntu0.4+esm9 | USN-8890-1 |
| Ubuntu Pro 16.04 LTS | libsoup2.4 | 2.52.2-1ubuntu0.3+esm8 | USN-8890-1 |
Azure Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Azure Linux 3 | libsoup | 3.4.4-16 | — |
Advisories 2
- USN-8890-2 libsoup3 vulnerabilities Ubuntu Security Notices (USN) · Oct 22, 2026
- USN-8890-1 libsoup2.4, libsoup3 vulnerabilities Ubuntu Security Notices (USN) · Oct 7, 2026