CVE-2026-82661

MEDIUMPre-NVD 5.45.4—
EchelonGraph scoreHIGH confidence

Score 5.4 from GitHub Security Advisory published 2026-08-31. a secondary CVSS source baseline 5.4; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
Trending — 3 sources updated this weekElevated
5.4EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 5.4Exploit: Elevated riskExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

Nodemailer before 8.0.9 fails to sanitize carriage return and line feed characters in list comment fields, allowing attackers to inject arbitrary message headers. An attacker with control over list.*.comment parameters can inject CRLF sequences to create additional headers in generated RFC822 messages, altering mail client behavior and message semantics.

CVSS v3
5.4
EG Score
5.4(high)
EG Risk
40(Track)
EG Risk 40/100SSVC: Track

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity54% × 45%
Exploitation40% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
9%
KEV
Not listed

Published

August 31, 2026

Last Modified

September 10, 2026

Advisory Details (2)

Auto-updated Aug 31, 2026
🔬 Proof of concept available. Patch available. Sources: github.
generic

Nodemailer CRLF Injection via List-* Header Comments | Advisories | VulnCheck

https://www.vulncheck.com/advisories/nodemailer-crlf-injection-via-list-header-comments
github Patch Available🟡 PoC Available

CRLF injection in Nodemailer List-* header comments allows arbitrary message header injection · Advisory · nodemailer/nodemailer · GitHub

https://github.com/nodemailer/nodemailer/security/advisories/GHSA-268h-hp4c-crq3

Vendor Advisories for CVE-2026-82661(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Affected Packages

(4 across 4 ecosystems)
Debian:12(1)
PackageVulnerable rangeFixed inDependents
node-nodemailer6.10.0+~6.4.17-1 ... 9.0.6+~8.0.1-1 (24 versions)——
Debian:13(1)
PackageVulnerable rangeFixed inDependents
node-nodemailer6.10.0+~6.4.17-1 ... 9.0.6+~8.0.1-1 (17 versions)——
Debian:14(1)
PackageVulnerable rangeFixed inDependents
node-nodemailer6.10.0+~6.4.17-1 ... 8.0.4+~7.0.11-2 (11 versions)8.0.11+~8.0.1-1—
npm(1)
PackageVulnerable rangeFixed inDependents
nodemailer—8.0.9—

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 21× in last 7d / 60× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-09-19 02:47 UTCEG score recompute
  2. 2026-09-19 02:47 UTCGHSA enrichment
  3. 2026-09-18 19:28 UTCEPSS rescore
  4. 2026-09-18 04:16 UTCEG score recompute
  5. 2026-09-18 04:16 UTCGHSA enrichment
  6. 2026-09-17 05:45 UTCEG score recompute
  7. 2026-09-17 05:44 UTCGHSA enrichment
  8. 2026-09-16 14:08 UTCEPSS rescore
  9. 2026-09-16 07:09 UTCEG score recompute
  10. 2026-09-16 07:09 UTCGHSA enrichment
  11. 2026-09-16 05:15 UTCEPSS rescore
  12. 2026-09-15 08:38 UTCEG score recompute
  13. 2026-09-15 08:38 UTCGHSA enrichment
  14. 2026-09-15 03:12 UTCEPSS rescore
  15. 2026-09-15 03:12 UTCEPSS rescore
  16. 2026-09-14 10:07 UTCEG score recompute
  17. 2026-09-14 10:07 UTCGHSA enrichment
  18. 2026-09-13 11:36 UTCEG score recompute
  19. 2026-09-13 11:36 UTCGHSA enrichment
  20. 2026-09-12 13:05 UTCEG score recompute
  21. 2026-09-12 13:05 UTCGHSA enrichment
  22. 2026-09-11 14:53 UTCEPSS rescore
  23. 2026-09-11 14:53 UTCEPSS rescore
  24. 2026-09-11 14:33 UTCEG score recompute
  25. 2026-09-11 14:33 UTCGHSA enrichment
Show 35 more
  1. 2026-09-10 16:02 UTCEG score recompute
  2. 2026-09-10 16:02 UTCGHSA enrichment
  3. 2026-09-10 07:08 UTCGHSA enrichment
  4. 2026-09-09 08:37 UTCEG score recompute
  5. 2026-09-09 08:37 UTCGHSA enrichment
  6. 2026-09-08 22:01 UTCEPSS rescore
  7. 2026-09-08 10:06 UTCEG score recompute
  8. 2026-09-08 10:05 UTCGHSA enrichment
  9. 2026-09-07 11:23 UTCEG score recompute
  10. 2026-09-07 11:23 UTCGHSA enrichment
  11. 2026-09-06 13:48 UTCEPSS rescore
  12. 2026-09-06 12:46 UTCEG score recompute
  13. 2026-09-06 12:46 UTCGHSA enrichment
  14. 2026-09-05 15:31 UTCEPSS rescore
  15. 2026-09-05 14:14 UTCGHSA enrichment
  16. 2026-09-04 15:43 UTCEG score recompute
  17. 2026-09-04 15:43 UTCGHSA enrichment
  18. 2026-09-04 05:07 UTCEPSS rescore
  19. 2026-09-03 17:10 UTCGHSA enrichment
  20. 2026-09-02 18:38 UTCEG score recompute
  21. 2026-09-02 18:37 UTCGHSA enrichment
  22. 2026-09-02 18:06 UTCEG score recompute
  23. 2026-09-02 18:06 UTCGHSA enrichment
  24. 2026-09-02 14:12 UTCEPSS rescore
  25. 2026-09-02 06:45 UTCEG score recompute
  26. 2026-09-02 06:45 UTCGHSA enrichment
  27. 2026-09-01 13:54 UTCEPSS rescore
  28. 2026-09-01 08:13 UTCEG score recompute
  29. 2026-09-01 08:12 UTCGHSA enrichment
  30. 2026-09-01 04:40 UTCEPSS rescore
  31. 2026-09-01 04:40 UTCEPSS rescore
  32. 2026-08-31 09:37 UTCEG score recompute
  33. 2026-08-31 09:37 UTCGHSA enrichment
  34. 2026-08-31 08:55 UTCEG score recompute
  35. 2026-08-31 08:52 UTCMITRE cvelistV5first tracked

Frequently asked(5)

What is CVE-2026-82661?
CVE-2026-82661 is a medium vulnerability published on August 31, 2026. Nodemailer before 8.0.9 fails to sanitize carriage return and line feed characters in list comment fields, allowing attackers to inject arbitrary message headers. An attacker with control over list.*.comment parameters can inject CRLF sequences to create additional headers in generated RFC822…
When was CVE-2026-82661 disclosed?
CVE-2026-82661 was first published in the National Vulnerability Database on August 31, 2026, with the most recent update on September 10, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-82661 actively exploited?
CVE-2026-82661 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 91.1% of all scored CVEs.
What is the CVSS score of CVE-2026-82661?
CVE-2026-82661 has a CVSS v3 base score of 5.4 (NVD).
How do I remediate CVE-2026-82661?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-82661, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-82661

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