CVE-2026-66338
Last modified
CVE-2026-66338 is a medium-severity vulnerability rated 5.4/10 on the CVSS scale. 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. EPSS estimates a 0.17% chance of exploitation in the next 30 days.
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.
Metrics
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:L/A:N
Weakness Enumeration
Affected Software
Source: CNA advisory (CVE.org). NVD analysis pending.
| Vendor | Product | Versions |
|---|---|---|
| Red Hat | Red Hat Enterprise Linux 10 | All versions |
| Red Hat | Red Hat Enterprise Linux 6 | All versions |
| Red Hat | Red Hat Enterprise Linux 7 | All versions |
| Red Hat | Red Hat Enterprise Linux 8 | All versions |
| Red Hat | Red Hat Enterprise Linux 9 | All versions |
References
Timeline
- Published
- Last Modified
- Status
- Awaiting Analysis
Frequently Asked Questions
What is CVE-2026-66338?
How severe is CVE-2026-66338?
How do I fix CVE-2026-66338?
How Strix Helps
- How Strix found a critical auth bypass in etcdStrix autonomously discovered a critical authentication bypass in etcd, later designated CVE-2026-33413.
- Autonomous PentestingAI agents that find and validate exploitable vulnerabilities like this one across your applications.
- PR ReviewsPentest every pull request so vulnerable code is caught before it ships to production.
- AI Penetration TestingHow AI-driven penetration testing continuously covers your attack surface.
Related CVEs from 2026
- CVE-2026-66321Access of resource using incompatible type ('type confusion'…9.6
- CVE-2026-66322Origin validation error in Microsoft Edge (Chromium-based) a…5.4
- CVE-2026-66325Server-side request forgery (ssrf) in Microsoft Edge (Chromi…6.1
- CVE-2026-66326Missing authorization in Microsoft Edge (Chromium-based) all…8.8
- CVE-2026-6633A security flaw has been discovered in Yifang CMS up to 2.0.…3.5
- CVE-2026-66337A flaw was found in libsoup. An unsigned integer underflow i…6.5
- CVE-2026-66339A flaw was found in libsoup. After a CONNECT tunnel is estab…6.5
- CVE-2026-6634A weakness has been identified in usememos memos up to 0.22.…6.3
- CVE-2026-66344NetKids iMark, provided by Integrated Systems Technologies, …6.7
- CVE-2026-66349The MMS server connection handler contains a flaw in its pro…6.9
- CVE-2026-6635A security vulnerability has been detected in rowboatlabs ro…7.3
- CVE-2026-6636A vulnerability was detected in p2r3 convert up to 6998584ac…4.3
Are you affected by CVE-2026-66338?
Run a free Strix scan to check your systems for this vulnerability.
Scan your code nowSource: NVD / NIST