CVE-2026-82509
V Programming Language net.http TLS Certificate Validation Bypass
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.
Fixes and workarounds
Fix
The reporting source identifies this reference as a patch. Check the advisory for affected versions and supported release branches.
Source: CNA: VulnCheckAffected products and versions
| Product | Versions | Authority |
|---|---|---|
| v vlang vlang/v
github |
≥ 0; ≤ 0.5.2 (affected, semver) https://github.com/vlang/v/commit/40774847a949722f (unaffected, git) Other versions: unaffected |
CNA: VulnCheck |
Version ranges are source assertions. Check the vendor advisory and your installed configuration before determining exposure.
CVSS assessments
| Version / score | Vector | Authority |
|---|---|---|
| 4.0 / 9.1 critical |
CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N | CNA: VulnCheck |
| 3.1 / 7.4 high |
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N | CNA: VulnCheck |
| 4.0 / 9.1 critical |
CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X | NVD: [email protected] |
| 3.1 / 7.4 high |
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N | NVD: [email protected] |
Exploit evidence
No exploit evidence in collected sources. This is not proof of no exploitation.
References
- https://github.com/vlang/v/security/advisories/GHSA-7g66-88pm-6gv6CNA: VulnCheck · vendor-advisory
- https://github.com/vlang/v/commit/40774847a949722f5d090706c050b806ceeacfd1CNA: VulnCheck · issue-tracking, patch
- https://www.vulncheck.com/advisories/v-programming-language-net-http-tls-certificate-validation-bypassCNA: VulnCheck · third-party-advisory
- https://github.com/vlang/v/commit/40774847a949722f5d090706c050b806ceeacfd1[email protected]
- https://github.com/vlang/v/security/advisories/GHSA-7g66-88pm-6gv6[email protected]
- https://www.vulncheck.com/advisories/v-programming-language-net-http-tls-certificate-validation-bypass[email protected]
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