Vulnerability-Lookup

CVE-2026-82509 (GCVE-0-2026-82509)

Vulnerability from cvelistv5 – Published: 2026-11-10 13:27 – Updated: 2026-11-10 13:28 X_Open Source

Title

V Programming Language net.http TLS Certificate Validation Bypass

Summary

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.

Severity

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

7.4 (High)


                        
                          CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N

CWE

CWE-295 - Improper Certificate Validation

Assigner

VulnCheck CNA

References

3 references

URL	Tags
https://github.com/vlang/v/security/advisories/GH…	vendor-advisory
https://github.com/vlang/v/commit/40774847a949722…	issue-trackingpatch
https://www.vulncheck.com/advisories/v-programmin…	third-party-advisory

Impacted products

1 product

Vendor	Product	Version
vlang	v	Affected: 0 , ≤ 0.5.2 (semver) Unaffected: https://github.com/vlang/v/commit/40774847a949722f (git)

Date Public

2026-11-07 00:00

Credits

Valentin Lobstein (Chocapikk)

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "packageURL": "pkg:github/vlang/v",
          "product": "v",
          "repo": "https://github.com/vlang/v",
          "vendor": "vlang",
          "versions": [
            {
              "lessThanOrEqual": "0.5.2",
              "status": "affected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "status": "unaffected",
              "version": "https://github.com/vlang/v/commit/40774847a949722f",
              "versionType": "git"
            }
          ]
        }
      ],
      "credits": [
        {
          "lang": "en",
          "type": "finder",
          "value": "Valentin Lobstein (Chocapikk)"
        }
      ],
      "datePublic": "2026-11-07T00:00:00.000Z",
      "descriptions": [
        {
          "lang": "en",
          "value": "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": [
        {
          "cvssV4_0": {
            "Automatable": "NOT_DEFINED",
            "Recovery": "NOT_DEFINED",
            "Safety": "NOT_DEFINED",
            "attackComplexity": "HIGH",
            "attackRequirements": "NONE",
            "attackVector": "NETWORK",
            "baseScore": 9.1,
            "baseSeverity": "CRITICAL",
            "exploitMaturity": "NOT_DEFINED",
            "privilegesRequired": "NONE",
            "providerUrgency": "NOT_DEFINED",
            "subAvailabilityImpact": "NONE",
            "subConfidentialityImpact": "NONE",
            "subIntegrityImpact": "NONE",
            "userInteraction": "NONE",
            "valueDensity": "NOT_DEFINED",
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            "version": "4.0",
            "vulnAvailabilityImpact": "NONE",
            "vulnConfidentialityImpact": "HIGH",
            "vulnIntegrityImpact": "HIGH",
            "vulnerabilityResponseEffort": "NOT_DEFINED"
          },
          "format": "CVSS",
          "scenarios": [
            {
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              "value": "GENERAL"
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          "cvssV3_1": {
            "attackComplexity": "HIGH",
            "attackVector": "NETWORK",
            "availabilityImpact": "NONE",
            "baseScore": 7.4,
            "baseSeverity": "HIGH",
            "confidentialityImpact": "HIGH",
            "integrityImpact": "HIGH",
            "privilegesRequired": "NONE",
            "scope": "UNCHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N",
            "version": "3.1"
          },
          "format": "CVSS",
          "scenarios": [
            {
              "lang": "en",
              "value": "GENERAL"
            }
          ]
        }
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      "problemTypes": [
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          "descriptions": [
            {
              "cweId": "CWE-295",
              "description": "Improper Certificate Validation",
              "lang": "en",
              "type": "CWE"
            }
          ]
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      ],
      "providerMetadata": {
        "dateUpdated": "2026-11-10T13:28:09.933Z",
        "orgId": "83251b91-4cc7-4094-a5c7-464a1b83ea10",
        "shortName": "VulnCheck"
      },
      "references": [
        {
          "name": "Github Security Advisory (GHSA-7g66-88pm-6gv6)",
          "tags": [
            "vendor-advisory"
          ],
          "url": "https://github.com/vlang/v/security/advisories/GHSA-7g66-88pm-6gv6"
        },
        {
          "name": "Patch Commit",
          "tags": [
            "issue-tracking",
            "patch"
          ],
          "url": "https://github.com/vlang/v/commit/40774847a949722f5d090706c050b806ceeacfd1"
        },
        {
          "name": "VulnCheck Advisory: V Programming Language net.http TLS Certificate Validation Bypass",
          "tags": [
            "third-party-advisory"
          ],
          "url": "https://www.vulncheck.com/advisories/v-programming-language-net-http-tls-certificate-validation-bypass"
        }
      ],
      "tags": [
        "x_open-source"
      ],
      "title": "V Programming Language net.http TLS Certificate Validation Bypass",
      "x_generator": {
        "engine": "vulncheck"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "83251b91-4cc7-4094-a5c7-464a1b83ea10",
    "assignerShortName": "VulnCheck",
    "cveId": "CVE-2026-82509",
    "datePublished": "2026-11-10T13:27:00.862Z",
    "dateReserved": "2026-08-29T17:20:57.080Z",
    "dateUpdated": "2026-11-10T13:28:09.933Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

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The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
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CVE-2026-82509 (GCVE-0-2026-82509)

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