CVE-2026-73430

MEDIUMPre-NVD 5.35.3—
EchelonGraph scoreMEDIUM confidence

This medium-severity CVE scores 5.3 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.3%, top 74% 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
5.3EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 5.3Exploit: None knownExposed: 0

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

Russh is a Rust SSH client & server library. Prior to 0.62.4, an unauthenticated SSH client can cause a denial of service by sending SSH_MSG_KEX_ECDH_INIT with a 32-byte all-zero Q_C value. Curve25519Kex::server_dh in russh/src/kex/curve25519.rs accepts the all-zero peer public value and computes an all-zero shared secret, after which compute_exchange_hash calls encode_mpint in russh/src/kex/mod.rs and indexes beyond the end of the input while skipping leading zero bytes. The resulting panic occurs before authentication and terminates the server key-exchange task. This issue is fixed in version 0.62.4.

CVSS v3
5.3
EG Score
5.3(medium)
EG Risk
39(Track)
EG Risk 39/100SSVC: 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
Severity53% × 45%
Exploitation0% × 40%
Automatability100% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
26%
KEV
Not listed

Published

August 12, 2026

Last Modified

August 13, 2026

Advisory Details (2)

Auto-updated Aug 12, 2026
Patch available. Sources: github_commit, github_release.
github_release Patch Available

v0.62.4

Patch available: Eugeny/russh v0.62.4

https://github.com/Eugeny/russh/releases/tag/v0.62.4
github_commit Patch Available

commit a7fc1eb57172 (Eugeny/russh)

Patch available: Eugeny/russh v0.62.4 (contains commit a7fc1eb57172)

https://github.com/Eugeny/russh/commit/a7fc1eb5717264e31c3c5f7dd849b73989a08f3d

Vendor Advisories for CVE-2026-73430(1)

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

Affected Packages

(1 across 1 ecosystem)
crates.io(1)
PackageVulnerable rangeFixed inDependents
russh—0.62.4—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 11× in last 7d / 31× 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. 2026-08-26 19:57 UTCEG score recompute
  2. 2026-08-26 14:47 UTCEPSS rescore
  3. 2026-08-25 19:52 UTCEG score recompute
  4. 2026-08-25 13:49 UTCEPSS rescore
  5. 2026-08-24 19:47 UTCEG score recompute
  6. 2026-08-23 19:42 UTCEG score recompute
  7. 2026-08-23 00:19 UTCEPSS rescore
  8. 2026-08-22 19:38 UTCEG score recompute
  9. 2026-08-21 23:49 UTCEPSS rescore
  10. 2026-08-21 19:33 UTCEG score recompute
  11. 2026-08-20 22:56 UTCEPSS rescore
  12. 2026-08-19 19:23 UTCEG score recompute
  13. 2026-08-19 17:04 UTCEPSS rescore
  14. 2026-08-18 19:18 UTCEG score recompute
  15. 2026-08-18 13:49 UTCEPSS rescore
  16. 2026-08-18 13:49 UTCEPSS rescore
  17. 2026-08-17 19:13 UTCEG score recompute
  18. 2026-08-17 13:47 UTCEPSS rescore
  19. 2026-08-16 18:34 UTCEG score recompute
  20. 2026-08-16 14:56 UTCEPSS rescore
  21. 2026-08-16 14:56 UTCEPSS rescore
  22. 2026-08-16 02:15 UTCEPSS rescore
  23. 2026-08-15 18:29 UTCEG score recompute
  24. 2026-08-15 01:31 UTCEPSS rescore
  25. 2026-08-14 18:24 UTCEG score recompute
Show 6 more
  1. 2026-08-13 22:00 UTCEPSS rescore
  2. 2026-08-13 18:19 UTCEG score recompute
  3. 2026-08-13 18:12 UTCEG score recompute
  4. 2026-08-12 21:20 UTCEG score recompute
  5. 2026-08-12 21:01 UTCEG score recompute
  6. 2026-08-12 21:00 UTCMITRE cvelistV5first tracked

Frequently asked(5)

What is CVE-2026-73430?
CVE-2026-73430 is a medium vulnerability published on August 12, 2026. Russh is a Rust SSH client & server library. Prior to 0.62.4, an unauthenticated SSH client can cause a denial of service by sending SSHMSGKEXECDHINIT with a 32-byte all-zero QC value. Curve25519Kex::serverdh in russh/src/kex/curve25519.rs accepts the all-zero peer public value and computes an…
When was CVE-2026-73430 disclosed?
CVE-2026-73430 was first published in the National Vulnerability Database on August 12, 2026, with the most recent update on August 13, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-73430 actively exploited?
CVE-2026-73430 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 74.3% of all scored CVEs.
What is the CVSS score of CVE-2026-73430?
CVE-2026-73430 has a CVSS v3 base score of 5.3 (NVD).
How do I remediate CVE-2026-73430?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-73430, 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-2026-73430

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