wget2 Improper Certificate Validation

published 2026-04-29 6 mo ago modified 2026-10-26 13 d ago also EUVD-2026-26285

cvss: 4.8; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.2%; EPSS 0.2% chance of exploitation in 30 days, percentile 4%
public exploits: 0; none known

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.

Patch / fix

fixed in 1

gnu wget2 2.2.2

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-1858 updated 2026-04-30 cvss 7.4

wget2: wget2: Improper certificate validation allows server impersonation

Red Hat All currently supported Red Hat products
not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation: none
Automatable: no
Technical impact: partial
Assessed: 6 mo ago (2026-04-30)

Exploit prediction

0.15% chance of exploitation in the next 30 days, higher than 4% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

tenable.com https://www.tenable.com/security/research/tra-2026-37 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by	version	score	vector
CNA	3.1	4.8	CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N

Affected products

gnu wget2

Classification

Weakness

CWE-20 Improper Input Validation

References

tenable.com /security/research/tra-2026-37
exploit, third-party-advisory

Sources

CVE List CVE-2026-1858
NVD CVE-2026-1858

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.

Summary