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TLS hostname verification bypass in Node.js via Unicode dot separator handling

IdentifiersCVE-2026-48618CWE-295

CVE-2026-48618 is a high-severity Node.js TLS hostname verification vulnerability affecting the supported 22.x, 24.x, and 26.x release lines. The flaw is caused by improper handling of Unicode dot separators during hostname verification, creating a mismatch between how hostnames are normalized by the resolver and by the certificate verifier. According to the provided content, this discrepancy can cause TLS wildcard-based authentication checks to be evaluated against a differently interpreted hostname than the one ultimately resolved, enabling host identity verification bypass under certain conditions.

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ANALYST BRIEF

Impact, mitigation & remediation

What it means. What to do now. Patch path, mitigations, and the assume-compromise checklist.

Impact

What an attacker gets, and what they’ve been doing with it.

Successful exploitation can bypass TLS hostname verification and wildcard-based certificate authentication, allowing an attacker to make a malicious endpoint appear valid for a target hostname under affected conditions. This undermines server identity validation and can enable man-in-the-middle style interception or redirection to attacker-controlled infrastructure where the client incorrectly accepts the presented certificate.

Mitigation

If you can’t patch tonight, do this now.

Until patching is completed, reduce exposure by avoiding reliance on vulnerable hostname verification paths where attacker influence over target hostnames or certificate matching is possible, and by restricting outbound TLS connections to trusted destinations through network controls. Additional temporary risk reduction may include explicit certificate pinning or stricter application-layer identity validation where operationally feasible. However, the authoritative mitigation is to upgrade to a fixed Node.js release.

Remediation

Patch, then assume compromise.

Upgrade Node.js to a patched supported release. The provided content identifies fixed versions as Node.js v22.23.0, v24.17.0, and v26.3.1, and separately as v22.23.1, v24.17.1, and v26.3.2 in subsequent reporting. Based on the available information, administrators should upgrade to the latest patched release available in the affected supported branch and avoid using end-of-life Node.js versions, which remain vulnerable.
PUBLIC EXPLOITS

Exploits

No public exploits tracked yet. Mallory keeps watching.

VALID 0 / 0 TOTALView more in app

No public exploit code observed for this vulnerability.

ACTIVITY FEED

Recent activity

9 sources tracked across advisories, community write-ups, and news. New activity surfaces here as Mallory finds it.

9 SOURCESView more in app
What this page doesn’t show

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Exposure mapping

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Threat actor evidence

Every observed campaign linking this CVE to a named adversary.

Associated malware

Malware families riding this exploit, with evidence and IOCs.

Detection signatures

YARA, Sigma, Snort, and vendor rules, auto-deployed to your SIEM.

Vendor-by-vendor mapping

Cross-references every affected SKU, including bundled OEM variants.

Social activity7

Community discussion across Reddit, Mastodon, and other social sources.

EXTERNAL REFERENCES
MITRE CVE
cve.org · CVE-2026-48618
NVD
nvd.nist.gov/vuln/detail/CVE-2026-48618
MITRE CWE · CWE-295
cwe.mitre.org