CVE-2026-82509

HIGHCVSS 7.4/10EPSS 0.23%

Last modified

CVE-2026-82509 is a high-severity vulnerability rated 7.4/10 on the CVSS scale. V programming language standard library net.http through version 0.5.2 prior to commit 4077484 contains a TLS certificate validation bypass vulnerability that allows on-path attackers to intercept HTTPS traffic by exploiting the default false value of SSLConnectConfig.validate and FetchConfig.validate, which completes TLS handshakes without verifying certificates in both the mbedtls and OpenSSL backends. Attackers can present an expired, self-signed, wrong-hostname, or untrusted-root certificate to successfully complete the handshake via http.get, http.post, or http.fetch, enabling interception or modification of HTTPS traffic unless validate: true is explicitly configured.. EPSS estimates a 0.23% chance of exploitation in the next 30 days.

Description

V programming language standard library net.http through version 0.5.2 prior to commit 4077484 contains a TLS certificate validation bypass vulnerability that allows on-path attackers to intercept HTTPS traffic by exploiting the default false value of SSLConnectConfig.validate and FetchConfig.validate, which completes TLS handshakes without verifying certificates in both the mbedtls and OpenSSL backends. Attackers can present an expired, self-signed, wrong-hostname, or untrusted-root certificate to successfully complete the handshake via http.get, http.post, or http.fetch, enabling interception or modification of HTTPS traffic unless validate: true is explicitly configured.

Metrics

Weakness Enumeration

Affected Software

Source: CNA advisory (CVE.org). NVD analysis pending.

VendorProductVersions
vlangv<= 0.5.2

References

Timeline

Published
Last Modified
Status
Awaiting Analysis

Frequently Asked Questions

What is CVE-2026-82509?
V programming language standard library net.http through version 0.5.2 prior to commit 4077484 contains a TLS certificate validation bypass vulnerability that allows on-path attackers to intercept HTTPS traffic by exploiting the default false value of SSLConnectConfig.validate and FetchConfig.validate, which completes TLS handshakes without verifying certificates in both the mbedtls and OpenSSL backends. Attackers can present an expired, self-signed, wrong-hostname, or untrusted-root certificate to successfully complete the handshake via http.get, http.post, or http.fetch, enabling interception or modification of HTTPS traffic unless validate: true is explicitly configured.
How severe is CVE-2026-82509?
CVE-2026-82509 has a CVSS score of 7.4/10 (HIGH severity). The EPSS model estimates a 0.23% probability of exploitation in the next 30 days.
How do I fix CVE-2026-82509?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

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Source: NVD / NIST