CVE-2026-33223

MEDIUMNVD 5.45.4—
EchelonGraph scoreMEDIUM confidence

This medium-severity CVE scores 5.4 under NVD CVSS v3. EPSS exploit probability: 0.2%, top 88% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: epss, nvd
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: None knownExposed: 0

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

NATS-Server is a High-Performance server for NATS.io, a cloud and edge native messaging system. Prior to versions 2.11.15 and 2.12.6, the NATS message header Nats-Request-Info: is supposed to be a guarantee of identity by the NATS server, but the stripping of this header from inbound messages was not fully effective. An attacker with valid credentials for any regular client interface could thus spoof their identity to services which rely upon this header. Versions 2.11.15 and 2.12.6 contain a fix. No known workarounds are available.

CVSS v3
5.4
EG Score
5.4(medium)
EG Risk
29(Track)
EG Risk 29/100SSVC: 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%
Exploitation0% × 40%
Automatability30% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
12%
KEV
Not listed

Published

March 25, 2026

Last Modified

June 17, 2026

Advisory Details (2)

Auto-updated Aug 6, 2026
Patch available. Sources: github.
github Patch Available

Internal identity header Nats-Request-Info spoofable · Advisory · nats-io/nats-server · GitHub

https://github.com/nats-io/nats-server/security/advisories/GHSA-pwx7-fx9r-hr4h
generic
https://advisories.nats.io/CVE/secnote-2026-09.txt

Affected Packages

(5 across 4 ecosystems)
Go(2)
PackageVulnerable rangeFixed inDependents
github.com/nats-io/nats-server———
github.com/nats-io/nats-server/v2—2.12.6—
Debian:12(1)
PackageVulnerable rangeFixed inDependents
nats-server2.10.1-1 ... 2.9.19-1 (14 versions)——
Debian:13(1)
PackageVulnerable rangeFixed inDependents
nats-server2.10.27-1, 2.12.4-1, 2.12.6-1, 2.14.1-1, 2.14.3-1——
Debian:14(1)
PackageVulnerable rangeFixed inDependents
nats-server2.10.27-1, 2.12.4-12.12.6-1—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 8× in last 7d / 28× 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. 2026-09-18 19:28 UTCEPSS rescore
  2. 2026-09-18 19:28 UTCEPSS rescore
  3. 2026-09-17 19:30 UTCEPSS rescore
  4. 2026-09-16 14:08 UTCEPSS rescore
  5. 2026-09-16 05:15 UTCEPSS rescore
  6. 2026-09-15 03:11 UTCEPSS rescore
  7. 2026-09-13 16:47 UTCEPSS rescore
  8. 2026-09-12 15:01 UTCEPSS rescore
  9. 2026-09-11 14:52 UTCEPSS rescore
  10. 2026-09-10 09:34 UTCEPSS rescore
  11. 2026-09-08 22:00 UTCEPSS rescore
  12. 2026-09-07 16:01 UTCEPSS rescore
  13. 2026-09-06 13:47 UTCEPSS rescore
  14. 2026-09-06 13:47 UTCEPSS rescore
  15. 2026-09-04 05:06 UTCEPSS rescore
  16. 2026-09-02 14:11 UTCEPSS rescore
  17. 2026-09-02 14:01 UTCOSV refresh
  18. 2026-09-01 13:53 UTCEPSS rescore
  19. 2026-08-30 19:17 UTCEPSS rescore
  20. 2026-08-30 01:22 UTCEPSS rescore
  21. 2026-08-28 21:41 UTCEPSS rescore
  22. 2026-08-27 14:25 UTCEPSS rescore
  23. 2026-08-26 14:46 UTCEPSS rescore
  24. 2026-08-25 13:49 UTCEPSS rescore
  25. 2026-08-24 14:17 UTCEPSS rescore
Show 33 more
  1. 2026-08-21 23:49 UTCEPSS rescore
  2. 2026-08-20 22:55 UTCEPSS rescore
  3. 2026-08-20 22:55 UTCEPSS rescore
  4. 2026-08-19 17:03 UTCEPSS rescore
  5. 2026-08-18 13:48 UTCEPSS rescore
  6. 2026-08-17 13:47 UTCEPSS rescore
  7. 2026-08-16 14:56 UTCEPSS rescore
  8. 2026-08-16 10:13 UTCEG score recompute
  9. 2026-08-16 02:14 UTCEPSS rescore
  10. 2026-08-14 06:31 UTCEG score recompute
  11. 2026-08-13 22:00 UTCEPSS rescore
  12. 2026-08-12 20:47 UTCEG score recompute
  13. 2026-08-12 13:50 UTCEPSS rescore
  14. 2026-08-11 08:59 UTCEG score recompute
  15. 2026-08-11 00:00 UTCEPSS rescore
  16. 2026-08-10 07:32 UTCEG score recompute
  17. 2026-08-09 13:46 UTCEPSS rescore
  18. 2026-08-09 06:06 UTCEG score recompute
  19. 2026-08-08 16:37 UTCEPSS rescore
  20. 2026-08-07 16:26 UTCEG score recompute
  21. 2026-08-06 13:46 UTCEPSS rescore
  22. 2026-08-06 00:56 UTCEG score recompute
  23. 2026-08-05 19:17 UTCEPSS rescore
  24. 2026-08-04 15:10 UTCEPSS rescore
  25. 2026-08-04 10:38 UTCEPSS rescore
  26. 2026-08-03 23:39 UTCEG score recompute
  27. 2026-08-03 10:36 UTCEPSS rescore
  28. 2026-08-02 15:27 UTCEG score recompute
  29. 2026-08-02 02:27 UTCEPSS rescore
  30. 2026-08-01 04:16 UTCEPSS rescore
  31. 2026-07-30 16:28 UTCEPSS rescore
  32. 2026-07-30 01:30 UTCEPSS rescore
  33. 2026-07-27 14:17 UTCEG score recompute

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-33223?
CVE-2026-33223 is a medium vulnerability published on March 25, 2026. NATS-Server is a High-Performance server for NATS.io, a cloud and edge native messaging system. Prior to versions 2.11.15 and 2.12.6, the NATS message header Nats-Request-Info: is supposed to be a guarantee of identity by the NATS server, but the stripping of this header from inbound messages was…
When was CVE-2026-33223 disclosed?
CVE-2026-33223 was first published in the National Vulnerability Database on March 25, 2026, with the most recent update on June 17, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-33223 actively exploited?
CVE-2026-33223 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 88.3% of all scored CVEs.
What is the CVSS score of CVE-2026-33223?
CVE-2026-33223 has a CVSS v3 base score of 5.4 (NVD).
How do I remediate CVE-2026-33223?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-33223, 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

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