Cyber Resilience

CVE-2026-2708

Redhat Enterprise Linux 10.0 … 9.0

Public PoC
Published
23 April 2026
Modified
04 May 2026
Patch / advisory
CVSS Score v3.1 3.7
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N
EPSS Score 0.0032 25th percentile
Risk Priority 16 floored blend · peak EPSS

Summary

CVE-2026-2708 is a low-severity HTTP Request/Response Smuggling (CWE-444) vulnerability in Redhat Enterprise Linux. Its CVSS base score is 3.7 (Low).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 25th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

The strongest mitigations our analysis identified map to SI-10 (Information Input Validation) and SC-7 (Boundary Protection) — see the control section below for these in your framework.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability Data

A request smuggling vulnerability exists in libsoup's HTTP/1 header parsing logic. The soup_message_headers_append_common() function in libsoup/soup-message-headers.c unconditionally appends each header value without validating for duplicate or conflicting Content-Length fields. This allows an attacker to send HTTP requests containing multiple Content-Length…

more

headers with differing values.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
Why these techniques?

Request smuggling in public-facing HTTP library directly enables remote exploitation of web applications (T1190).

Confidence: HIGH · MITRE ATT&CK Enterprise v19.0

CVEs Like This One

CVE-2026-1801Same product: Gnome Libsoup
CVE-2026-1467Same product: Gnome Libsoup
CVE-2026-2443Same product: Gnome Libsoup
CVE-2026-1536Same product: Gnome Libsoup
CVE-2026-3633Same product: Gnome Libsoup
CVE-2026-3634Same product: Gnome Libsoup
CVE-2026-12549Same product: Gnome Libsoup
CVE-2026-3632Same product: Gnome Libsoup
CVE-2026-3099Same product: Gnome Libsoup
CVE-2026-2436Same product: Gnome Libsoup

Affected Assets

gnome
libsoup
all versions
redhat
enterprise linux
10.0, 6.0, 7.0, 8.0, 9.0

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)
  • SI-10 Information Input Validation
  • SC-7 Boundary Protection
Detect
Catch it (NIST detect / respond)
  • SC-7 Boundary Protection
  • SI-4 System Monitoring
Harden
Shrink the surface (DISA STIG)

Validate
Prove the fix (OWASP ASVS)
  • V4.1.3
  • V4.2.4
  • V1.5.3
  • V4.1.1

Mitigating Controls (NIST 800-53 r5) AI

prevent

Rejects HTTP/1 requests containing duplicate or conflicting Content-Length headers before they reach libsoup's unconditional append logic.

preventdetect

Boundary devices (WAFs/proxies) can enforce HTTP header canonicalization and drop smuggling attempts before they reach the vulnerable soup_message_headers_append_common function.

detect

Monitors inbound HTTP traffic for anomalous multi-valued Content-Length headers indicative of request-smuggling attempts against libsoup.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-01 mostly match
prevents

Configuration management can enforce uniform HTTP parsing rules across intermediaries, directly mitigating inconsistent interpretation.

DE.CM-01 partial match
prevents

Network monitoring can detect smuggling attempts via anomalous HTTP traffic or logs, while eliminating the inconsistency directly aids detection of such events.

PR.IR-01 partial match
prevents

Network protections can enforce consistent HTTP proxy/firewall behavior to block smuggling, and removing the weakness helps prevent unauthorized access via request smuggling.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

detects

Security testing can detect HTTP request smuggling vulnerabilities in intermediary components.

degrades

Network security controls can enforce consistent HTTP parsing and proxy behavior that mitigates request smuggling.

degrades

Secure network services include hardening proxies and gateways against inconsistent HTTP interpretation.

prevents

Secure SDLC practices require threat modeling and testing for HTTP parsing inconsistencies in intermediaries.

prevents

Application security requirements can mandate strict HTTP message validation and canonicalization.

prevents

Secure architecture principles include consistent protocol handling and defense-in-depth for proxies.

References