CVE-2026-1858 | wget2 Improper Certificate Validation

Exp

wget2 accepts a server certificate with incorrect Key Usage (KU) or Extended Key Usage (EKU). If the attackers compromise a certificate (with the associated private key) issued for a different purpose, they may be able to reuse it for TLS server authentication.

Published: 2026-04-29 Last update: 2026-05-05 Assigner: [email protected] Source: [email protected]
NVD Status：Analyzed，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2026-1858 is rated Exploit Available (50/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.01%). 1 public exploit reference(s) are indexed (Exploit-DB). Public exploits are available—assess exposure, apply mitigations, and prioritize patching.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Public exploit references (Exploit-DB) for CVE-2026-1858

EDB-ID Source Kind Published Link
— nvd_ref exploit_tag Exploit-DB ↗

Exploit prediction scoring system (EPSS) score for CVE-2026-1858

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-04-30 — 0.01% —

Full EPSS history (1 record total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-1858

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
4.8 3.1 MEDIUM
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:H)
Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:L)
Some sensitive info could get out, but not a total data dump.
Integrity (I:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:N)
Service keeps running; no real outage angle.
 2.2 2.5 [email protected]

Weakness enumeration for CVE-2026-1858

GitHub Security Advisory for CVE-2026-1858

GHSA-9h5h-4q77-cphm · Severity: medium — wget2 accepts a server certificate with incorrect Key Usage (KU) or Extended Key Usage (EKU). If...

OS Trackers for CVE-2026-1858

vendor priority summary link
debian not yet assigned CVE-2026-1858 not yet assigned priority: Debian including 1 source packages (wget2), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): open 5. https://security-tracker.debian.org/tracker/CVE-2026-1858
suse medium — https://www.suse.com/security/cve/CVE-2026-1858/
ubuntu medium CVE-2026-1858 medium priority: Ubuntu including 1 source packages (wget2), 7 status rows across 7 suites (bionic, focal, jammy, noble, questing, resolute, upstream): needs-triage 7. https://ubuntu.com/security/CVE-2026-1858

Affected software / configurations for CVE-2026-1858

Vendor Product Version Raw CPE
gnu wget2 <= 2.2.1 cpe:2.3:a:gnu:wget2:*:*:*:*:*:*:*:*

References for CVE-2026-1858

URL Tags
https://www.tenable.com/security/research/tra-2026-37 Exploit Third Party Advisory
cvelogic Threat Intelligence