Red HatCVE-2026-66338
Red Hat libsoup: request smuggling
Medium5.4CVE-2026-66338 · Published Jul 24, 2026 · updated Aug 24, 2026
A flaw was found in libsoup. The chunked transfer encoding parser uses a permissive parsing function for chunk sizes that silently accepts inputs violating RFC 9112, including leading whitespace, plus sign prefixes, and trailing invalid characters. When libsoup operates behind a strict frontend proxy, this parsing differential can be exploited to smuggle HTTP requests.
Affected versions
| Package | Affected | Fixed in |
|---|---|---|
| Red Hat Enterprise Linux 10 Product | all versions | No fix yet |
| Red Hat Enterprise Linux 6 Product | all versions | No fix yet |
| Red Hat Enterprise Linux 7 Product | all versions | No fix yet |
| Red Hat Enterprise Linux 8 Product | all versions | No fix yet |
| Red Hat Enterprise Linux 9 Product | all versions | No fix yet |
Details and references
- CVSS 3.1
- CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:L/A:N
- Severity from
- the vendor (its own CVE record or advisory)
- Weakness
- CWE-444
More Red Hat advisories
All Red Hat| Date | Advisory | Severity | Fixed in |
|---|---|---|---|
| Jul 24 | Red Hat libsoup: information disclosure | Medium6.5 | No fix yet |
| Jul 24 | Red Hat libsoup. An unsigned integer underflow: integer overflow | Medium6.5 | No fix yet |
| Jul 24 | A flaw was found in the cluster-proxy service-proxy component used in Red Hat... | High8.5 | No fix yet |
| Jul 24 | Red Hat pki-core: improper authorization | Low3.1 | No fix yet |
| Jul 24 | Red Hat role-users endpoint: insecure direct object reference | Medium6.5 | No fix yet |
| Jul 24 | Red Hat Keycloak Admin REST API: information disclosure | Medium5.5 | No fix yet |