CVE-2026-66338— Libsoup: libsoup: http request smuggling via permissive chunk-size parsing in soup_body_input_stream_read_chunked()
Quick assessment
Affected
Red Hat Red Hat Enterprise Linux 10
Exploitation
No confirmed in-the-wild exploitation; assess based on exposure
Recommended action
Check the vendor advisory and references for a fixed version. If immediate upgrade is impossible, restrict exposure and increase monitoring.
libsoup是libsoup团队开源的一个HTTP库。 libsoup存在输入验证错误漏洞，该漏洞源于分块传输编码解析器对块大小使用宽松的解析函数，可能导致HTTP请求走私。
Possible ATT&CK Techniques 2 AI
T1557 · Adversary-in-the-Middle T1190 · Exploit Public-Facing ApplicationAffected Version Matrix 5
| Vendor | Product | Version Range | Status |
|---|---|---|---|
| Red Hat | Red Hat Enterprise Linux 10 | any |
affected |
| Red Hat | Red Hat Enterprise Linux 6 | any |
affected |
| Red Hat | Red Hat Enterprise Linux 7 | any |
affected |
| Red Hat | Red Hat Enterprise Linux 8 | any |
affected |
| Red Hat | Red Hat Enterprise Linux 9 | any |
affected |
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I. Basic Information for CVE-2026-66338
Vulnerability Information
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Vulnerability Title
Libsoup: libsoup: http request smuggling via permissive chunk-size parsing in soup_body_input_stream_read_chunked()
Source: CVE Program / CVE List V5
Vulnerability Description
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.
Source: CVE Program / CVE List V5
CVSS Information
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:L/A:N
Source: CVE Program / CVE List V5
Vulnerability Type
HTTP请求的解释不一致性(HTTP请求私运)
Source: CVE Program / CVE List V5
Vulnerability Title
libsoup 输入验证错误漏洞
Source: CNNVD (China National Vulnerability Database)
Vulnerability Description
libsoup是libsoup团队开源的一个HTTP库。 libsoup存在输入验证错误漏洞，该漏洞源于分块传输编码解析器对块大小使用宽松的解析函数，可能导致HTTP请求走私。
Source: CNNVD (China National Vulnerability Database)
CVSS Information
N/A
Source: CNNVD (China National Vulnerability Database)
Vulnerability Type
N/A
Source: CNNVD (China National Vulnerability Database)
Affected Products
| Vendor | Product | Affected Versions | CPE | Subscribe |
|---|---|---|---|---|
| Red Hat | Red Hat Enterprise Linux 10 | - |
cpe:/a:redhat:enterprise_linux:10
|
|
| Red Hat | Red Hat Enterprise Linux 6 | - |
cpe:/o:redhat:rhel_els:6
|
|
| Red Hat | Red Hat Enterprise Linux 7 | - |
cpe:/o:redhat:rhel_els:7
|
|
| Red Hat | Red Hat Enterprise Linux 8 | - |
cpe:/a:redhat:enterprise_linux:8
|
|
| Red Hat | Red Hat Enterprise Linux 9 | - |
cpe:/a:redhat:enterprise_linux:9
|
|
II. Public POCs for CVE-2026-66338
| # | POC Description | Source Link | Shenlong Link |
|---|
AI-Generated POC
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Vendor Advisories for CVE-2026-66338 (2)
Same Patch Batch · Red Hat · 2026-07-24 · 10 CVEs total
| CVE-2026-17107 | 8.5 HIGH | Cluster-proxy: impersonation-header injection grants cluster-admin on every managed cluste |
| CVE-2026-66337 | 6.5 MEDIUM | Libsoup: libsoup: heap buffer over-read via integer underflow in soup_filter_input_stream_ |
| CVE-2026-66339 | 6.5 MEDIUM | Libsoup: libsoup: proxy credentials leak to destination server via proxy-authorization hea |
| CVE-2026-17059 | 6.5 MEDIUM | Keycloak-services: keycloak-services: information disclosure via role-users endpoint bypas |
| CVE-2026-17048 | 5.5 MEDIUM | Keycloak-services: keycloak-services: vault-resolved rotated client secrets leaked via adm |
| CVE-2026-16743 | 5.5 MEDIUM | Accountsservice: accountsservice: arbitrary file read via seticonfile for systemd-homed us |
| CVE-2026-16730 | 5.5 MEDIUM | Dbus-broker: dbus-broker: session bus denial of service via emfile during peer setup |
| CVE-2026-16910 | 5.5 MEDIUM | Quay: ssrf in red hat quay notification webhooks (slack/generic) |
| CVE-2026-17039 | 3.1 LOW | Pki-core: dogtag-pki: redhat-pki: pki-core: ca renewal request processing omits realm auth |
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