CVE-2026-82662: Nodemailer before 8.0.8 TLS Certificate Validation Bypass
Vulnerability summary
CVE-2026-82662 is a high (CVSS 8.3) Improper Certificate Validation vulnerability in nodemailer. EPSS estimates a 0.19% chance of exploitation in the next 30 days, higher than 8.9% of scored vulnerabilities.
Severe, CVSS 8.3 (CVE.org); no exploitation reported by the 5 checked sources; EPSS 0% (FIRST, 03-11-2026)
Source freshness unavailable
How is this decided?Advisory lineage
Upstream 1 · Downstream 0Timeline
- 31-08-2026PublishedVulnerability first disclosed.
- 01-09-2026Last modifiedVulnerability information updated.
Description
Nodemailer before 8.0.8 disables TLS certificate verification in lib/fetch/index.js through rejectUnauthorized: false, allowing attackers to intercept OAuth2 token requests. Attackers in a machine-in-the-middle position can capture OAuth client secrets, refresh tokens, and access tokens transmitted over compromised HTTPS connections.
CVSS metrics
13 scores · 7 sources · 2 versions- OSV · UbuntuEcosystem advisory · calculated8.3HighCVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:L/VA:N/SC:N/SI:N/SA:N
- OSV · DebianEcosystem advisory · calculated8.3HighCVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:L/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
- OSV · WolfiEcosystem advisory · calculated8.3HighCVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:L/VA:N/SC:N/SI:N/SA:N
- OSV · NpmEcosystem advisory · calculated8.3HighCVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:L/VA:N/SC:N/SI:N/SA:N
- OSV · ChainguardEcosystem advisory · calculated8.3HighCVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:L/VA:N/SC:N/SI:N/SA:N
- NVDNIST8.3HighCVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:L/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
- OSV · UbuntuEcosystem advisory · calculated6.5MediumCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:L/A:N
- OSV · WolfiEcosystem advisory · calculated6.5MediumCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:L/A:N
- OSV · NpmEcosystem advisory · calculated6.5MediumCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:L/A:N
- OSV · ChainguardEcosystem advisory · calculated6.5MediumCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:L/A:N
- NVDNIST6.5MediumCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:L/A:N
EPSS trend
Probability
0.19%
Chance of exploitation in the next 30 days
Percentile
9%
Versus all other CVEs
30-day change
No change 0.00 pp
From 0.19% on 04-10-2026
Known exploited
Compare KEV catalogs
CISA KEVNot in the CISA KEV catalog.
ENISA CNWNot in the ENISA CNW catalog.
CIRCLNot in the CIRCL catalog.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Known conditions: network-reachable, no authentication, no user interaction (CVSS vector). Other conditions: not stated in public data.
Chainguard9 products
- kibana-7All versions (No fix recorded)
- kibana-9.4< 9.4.2-r6
- kibana-9.4-iamguarded< 9.4.2-r6
- langfuse-3< 3.191.0-r0
- langfuse-3-compat< 3.225.7-r6
Wolfi3 products
- langfuse-3< 3.191.0-r0
- langfuse-3-compat< 3.225.7-r6
- langfuse-3-worker< 3.191.0-r0
Debian1 product
- node-nodemailerAll versions (No fix recorded) | < 8.0.11+~8.0.1-1
Nodemailer1 product
- nodemailer< 8.0.8
Npm1 product
- nodemailer< 8.0.8
Ubuntu1 product
- node-nodemailerAll versions (No fix recorded)
6 vendors · 16 products
References
8 links- github.com/nodemailer/nodemailer/security/advisories/GHSA-r7g4-qg5f-qqm2Vendor AdvisoryREPORTWEBAdvisory
- www.vulncheck.com/advisories/nodemailer-before-8.0.8-tls-certificate-validation-bypassThird Party AdvisoryREPORTWEBAdvisory
