CVE-2026-66338
published 2026-07-24CVE-2026-66338: 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…
PriorityP340high7.2CVSS 3.1
AVNACLPRNUINSCCLILAN
EPSS
0.29%
20.2th percentile
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
7 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| debian | libsoup3 | — | — |
| gnome | libsoup | — | — |
| redhat | enterprise_linux | — | — |
| redhat | enterprise_linux | — | — |
| redhat | enterprise_linux | — | — |
| redhat | enterprise_linux | — | — |
| redhat | enterprise_linux | — | — |
CVSS provenance
nvdv3.17.2HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N
vendor_redhat6.5MEDIUM
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VulDB
Red Hat Enterprise Linux Chunked Transfer Encoding Parser encoding error (EUVD-2026-48752)
vuldb·2026-07-25·CVSS 5.4
CVE-2026-66338 [MEDIUM] Red Hat Enterprise Linux Chunked Transfer Encoding Parser encoding error (EUVD-2026-48752)
A vulnerability, which was classified as very critical, was found in Red Hat Enterprise Linux. This affects an unknown function of the component Chunked Transfer Encoding Parser. The manipulation results in encoding error.
This vulnerability was named CVE-2026-66338. The attack may be performed from remote. There is no available exploit.
GHSA
A flaw was found in libsoup.
ghsa_unreviewed·2026-07-25
CVE-2026-66338 [MEDIUM] CWE-444 A flaw was found in libsoup.
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.
Red Hat
libsoup: libsoup: HTTP Request Smuggling via permissive chunk-size parsing in soup_body_input_stream_read_chunked()
vendor_redhat·2026-06-05·CVSS 6.5
CVE-2026-66338 [MEDIUM] CWE-444 libsoup: libsoup: HTTP Request Smuggling via permissive chunk-size parsing in soup_body_input_stream_read_chunked()
libsoup: libsoup: HTTP Request Smuggling via permissive chunk-size parsing in soup_body_input_stream_read_chunked()
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.
Statement: A flaw was found in libsoup where the chunked transfer encoding parser uses strtoul() to parse chunk sizes without strict validation, silently accepting inputs that violate RFC 9112. When libsoup operates behind a strict frontend proxy, this parsing differential can be exploited to smuggle HTTP req
No detection rules found.
No public exploits indexed.
2026-07-24
Published