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Linux Distros Unpatched Vulnerability : CVE-2026-90588

low Nessus Plugin ID 379196

Synopsis

The Linux/Unix host has one or more packages installed with a vulnerability that the vendor indicates will not be patched.

Description

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available.

 - The HTTP client's debug helper print_header_field() in subsys/net/lib/http/http_client.c formatted an http_parser data-callback slice with a %s conversion: snprintk(output, len + 1, %s, str). The parser hands its callbacks a pointer and a length into the caller's receive buffer, and those bytes are not NUL terminated. The size argument of snprintk() bounds only the destination, while the %s conversion measures the source first lib/os/cbprintf_complete.c uses strlen() when no precision is given, and lib/os/cbprintf_nano.c uses strlen() unconditionally so the read walks past the end of the header field and past the end of the receive buffer until it finds a zero byte. The slice reaches the helper from on_url(), on_header_field() and on_header_value(), which the parser invokes on bytes that http_wait_data() read straight off the socket into the application-supplied recv_buf. A malicious or compromised HTTP server, or an attacker able to answer a plaintext request, therefore controls both the header field and the bytes that follow it in the buffer, and can guarantee that no zero byte appears before the buffer ends, forcing the over-read. The in-tree tests/net/lib/http_client suite reproduces the over-read under CONFIG_ASAN=y on an ordinary GET. The impact is bounded. The whole helper body is compiled only when the HTTP client log module is explicitly set to Debug (CONFIG_NET_HTTP_LOG_LEVEL_DBG=y, which the global CONFIG_LOG_DEFAULT_LEVEL does not set), so default builds are unaffected. No out-of-bounds write occurs and none of the over-read bytes are emitted into the log, so there is no information disclosure; the consequence is an out-of-bounds read that can fault and panic the device where the buffer abuts an unmapped or MPU/MMU-protected region. The fix copies exactly the len bytes the parser offered with memcpy() and terminates them, instead of relying on a %s conversion (a %.*s precision would not have sufficed, since cbprintf_nano.c measures the source in full before applying it). (CVE-2026-90588)

Note that Nessus relies on the presence of the package as reported by the vendor.

Solution

There is no known solution at this time.

See Also

https://ubuntu.com/security/CVE-2026-90588

Plugin Details

Severity: Low

ID: 379196

File Name: unpatched_CVE_2026_90588.nasl

Version: 1.1

Type: Local

Agent: unix

Family: Misc.

Published: 11/11/2026

Updated: 11/11/2026

Supported Sensors: Frictionless Assessment AWS, Frictionless Assessment Azure, Frictionless Assessment Agent, Nessus Agent, Agentless Assessment, Tenable Cloud Security, Tenable Self-Hosted Container Security, Nessus

Risk Information

VPR

Risk Factor: Low

Score: 1.2

Percentile: 0.01

CVSS v2

Risk Factor: Medium

Base Score: 5

Temporal Score: 4.3

Vector: CVSS2#AV:N/AC:L/Au:N/C:P/I:N/A:N

CVSS Score Source: CVE-2026-90588

CVSS v3

Risk Factor: Low

Base Score: 3.7

Temporal Score: 3.4

Vector: CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L

Temporal Vector: CVSS:3.0/E:U/RL:U/RC:C

Vulnerability Information

CPE: cpe:/o:canonical:ubuntu_linux:16.04:-:lts, cpe:/o:canonical:ubuntu_linux:18.04:-:lts, cpe:/o:canonical:ubuntu_linux:20.04:-:lts, cpe:/o:canonical:ubuntu_linux:22.04:-:lts, cpe:/o:canonical:ubuntu_linux:24.04:-:lts, cpe:/o:canonical:ubuntu_linux:26.04:-:lts, cpe:/o:canonical:ubuntu_linux:26.10, p-cpe:/a:canonical:ubuntu_linux:zephyr

Required KB Items: Host/local_checks_enabled, Host/cpu, global_settings/vendor_unpatched, Host/OS/identifier

Exploit Ease: No known exploits are available

Vulnerability Publication Date: 11/9/2026

Reference Information

CVE: CVE-2026-90588