CVE-2026-59920

MEDIUMPre-NVD 6.56.5—
EchelonGraph scoreMEDIUM confidence

This medium-severity CVE scores 6.5 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.2%, top 85% 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, secondary
Elevated
6.5EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 6.5Exploit: Elevated riskExposed: 0

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

Netty is an asynchronous, event-driven network application framework. In versions prior to 4.1.136.Final and 4.2.16.Final, Netty's STOMP encoder ( StompSubframeEncoder ) does not escape or validate header values in  CONNECT  and  CONNECTED  frames, so raw newline ( \n ) characters in a header value are written directly to the wire, allowing an attacker who controls a header value to inject additional STOMP headers. This happens because the encoder intentionally skips escaping for CONNECT/CONNECTED frames per the STOMP 1.2 specification but never rejects the raw newlines, and since a broker parses each line as a separate header, an attacker controlling a value such as a user-supplied login or passcode can overwrite connection parameters or add authentication/role headers to bypass authentication or escalate privileges (the actual impact is broker-dependent). The issue is fixed in versions 4.1.136.Final and 4.2.16.Final.

CVSS v3
6.5
EG Score
6.5(medium)
EG Risk
45(Track)
EG Risk 45/100SSVC: 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
Severity65% × 45%
Exploitation40% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
15%
KEV
Not listed

Published

July 22, 2026

Last Modified

August 6, 2026

Advisory Details (1)

Auto-updated Jul 29, 2026
🔬 Proof of concept available. Patch available. Sources: github.
github Patch Available🟡 PoC Available

STOMP CONNECT Frame Header Injection in Netty · Advisory · netty/netty · GitHub

https://github.com/netty/netty/security/advisories/GHSA-3g8r-4pfx-jmfh

Vendor Advisories for CVE-2026-59920(1)

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

Affected Packages

(5 across 5 ecosystems)
Debian:11(1)
PackageVulnerable rangeFixed inDependents
netty1:4.1.48-10 ... 1:4.1.48-9 (16 versions)——
Debian:12(1)
PackageVulnerable rangeFixed inDependents
netty1:4.1.48-10 ... 1:4.1.48-9 (12 versions)——
Debian:13(1)
PackageVulnerable rangeFixed inDependents
netty1:4.1.48-10 ... 1:4.1.48-16 (8 versions)——
Debian:14(1)
PackageVulnerable rangeFixed inDependents
netty1:4.1.48-10 ... 1:4.1.48-16 (7 versions)——
Maven(1)
PackageVulnerable rangeFixed inDependents
io.netty:netty-codec-stomp4.1.0.Beta1 ... 4.1.99.Final (151 versions)4.1.136.Final—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 9× in last 7d / 46× 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. 2026-09-15 03:11 UTCEPSS rescore
  2. 2026-09-13 18:10 UTCEG score recompute
  3. 2026-09-13 16:47 UTCEPSS rescore
  4. 2026-09-12 19:19 UTCEG score recompute
  5. 2026-09-11 20:28 UTCEG score recompute
  6. 2026-09-11 14:53 UTCEPSS rescore
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  9. 2026-09-09 09:11 UTCEG score recompute
  10. 2026-09-08 22:01 UTCEPSS rescore
  11. 2026-09-07 21:39 UTCEG score recompute
  12. 2026-09-07 16:01 UTCEPSS rescore
  13. 2026-09-06 18:32 UTCEG score recompute
  14. 2026-09-06 13:47 UTCEPSS rescore
  15. 2026-09-05 19:33 UTCEG score recompute
  16. 2026-09-04 13:39 UTCEG score recompute
  17. 2026-09-04 05:07 UTCEPSS rescore
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  19. 2026-09-01 23:36 UTCEG score recompute
  20. 2026-09-01 13:54 UTCEPSS rescore
  21. 2026-09-01 04:40 UTCEPSS rescore
  22. 2026-08-30 23:40 UTCEG score recompute
  23. 2026-08-30 19:17 UTCEPSS rescore
  24. 2026-08-30 01:22 UTCEPSS rescore
  25. 2026-08-30 00:50 UTCEG score recompute
Show 59 more
  1. 2026-08-28 21:42 UTCEPSS rescore
  2. 2026-08-27 21:10 UTCEG score recompute
  3. 2026-08-27 14:25 UTCEPSS rescore
  4. 2026-08-26 21:17 UTCEG score recompute
  5. 2026-08-26 14:46 UTCEPSS rescore
  6. 2026-08-25 22:19 UTCEG score recompute
  7. 2026-08-25 13:49 UTCEPSS rescore
  8. 2026-08-24 23:00 UTCEG score recompute
  9. 2026-08-23 01:18 UTCEG score recompute
  10. 2026-08-23 00:19 UTCEPSS rescore
  11. 2026-08-22 02:27 UTCEG score recompute
  12. 2026-08-21 23:49 UTCEPSS rescore
  13. 2026-08-21 03:25 UTCEG score recompute
  14. 2026-08-20 22:55 UTCEPSS rescore
  15. 2026-08-20 04:34 UTCEG score recompute
  16. 2026-08-19 17:04 UTCEPSS rescore
  17. 2026-08-19 05:43 UTCEG score recompute
  18. 2026-08-18 13:48 UTCEPSS rescore
  19. 2026-08-18 06:52 UTCEG score recompute
  20. 2026-08-17 13:47 UTCEPSS rescore
  21. 2026-08-17 07:58 UTCEG score recompute
  22. 2026-08-16 14:56 UTCEPSS rescore
  23. 2026-08-16 09:07 UTCEG score recompute
  24. 2026-08-16 02:14 UTCEPSS rescore
  25. 2026-08-15 10:17 UTCEG score recompute
  26. 2026-08-15 01:30 UTCEPSS rescore
  27. 2026-08-14 11:25 UTCEG score recompute
  28. 2026-08-13 22:00 UTCEPSS rescore
  29. 2026-08-13 12:34 UTCEG score recompute
  30. 2026-08-12 13:51 UTCEPSS rescore
  31. 2026-08-11 14:51 UTCEG score recompute
  32. 2026-08-11 00:00 UTCEPSS rescore
  33. 2026-08-09 17:07 UTCEG score recompute
  34. 2026-08-09 13:46 UTCEPSS rescore
  35. 2026-08-08 18:17 UTCEG score recompute
  36. 2026-08-08 16:37 UTCEPSS rescore
  37. 2026-08-07 19:26 UTCEG score recompute
  38. 2026-08-06 20:35 UTCEG score recompute
  39. 2026-08-06 13:47 UTCEPSS rescore
  40. 2026-08-06 10:23 UTCEG score recompute
  41. 2026-08-05 19:17 UTCEPSS rescore
  42. 2026-08-05 11:32 UTCEG score recompute
  43. 2026-08-04 15:10 UTCEPSS rescore
  44. 2026-08-04 12:41 UTCEG score recompute
  45. 2026-08-04 10:39 UTCEPSS rescore
  46. 2026-08-03 12:12 UTCEG score recompute
  47. 2026-08-03 10:36 UTCEPSS rescore
  48. 2026-08-02 13:19 UTCEG score recompute
  49. 2026-08-02 02:27 UTCEPSS rescore
  50. 2026-08-01 14:28 UTCEG score recompute
  51. 2026-08-01 04:16 UTCEPSS rescore
  52. 2026-07-30 16:47 UTCEG score recompute
  53. 2026-07-30 16:28 UTCEPSS rescore
  54. 2026-07-29 20:23 UTCEG score recompute
  55. 2026-07-29 20:03 UTCEG score recompute
  56. 2026-07-29 18:31 UTCEG score recompute
  57. 2026-07-27 08:39 UTCEG score recompute
  58. 2026-07-23 03:21 UTCEG score recompute
  59. 2026-07-22 22:26 UTCEG score recompute

Frequently asked(5)

What is CVE-2026-59920?
CVE-2026-59920 is a medium vulnerability published on July 22, 2026. Netty is an asynchronous, event-driven network application framework. In versions prior to 4.1.136.Final and 4.2.16.Final, Netty's STOMP encoder ( StompSubframeEncoder ) does not escape or validate header values in CONNECT and CONNECTED frames, so raw newline ( \n ) characters in a header value are…
When was CVE-2026-59920 disclosed?
CVE-2026-59920 was first published in the National Vulnerability Database on July 22, 2026, with the most recent update on August 6, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-59920 actively exploited?
CVE-2026-59920 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 85.0% of all scored CVEs.
What is the CVSS score of CVE-2026-59920?
CVE-2026-59920 has a CVSS v3 base score of 6.5 (NVD).
How do I remediate CVE-2026-59920?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-59920, 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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