CVE-2026-63403

HIGHPre-NVD 8.78.7—
EchelonGraph scoreMEDIUM confidence

This high-severity CVE scores 8.7 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.4%, top 64% 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
8.7EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 8.7Exploit: Elevated riskExposed: 0

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

Faktory is a language-agnostic background job server. In versions prior to 1.10.0, the server is vulnerable to an unauthenticated denial of service in which a single malformed command crashes the entire process. Its wire protocol is line-based, and several command handlers slice or index the received line at a fixed offset, such as cmd[5:] for PUSH or qs[0] for QUEUE, without checking that a payload is present. Sending a bare verb with no payload, for example PUSH, ACK, FAIL, BEAT, PUSHB, or QUEUE, triggers a Go slice or index out-of-range panic. Because the codebase has no recover() anywhere in the command-dispatch path, an unrecovered panic in a handler goroutine terminates the whole Go process rather than just that connection, instantly disconnecting every other client, worker, and in-flight job. The attack requires only a connection to the command port and completion of the trivial handshake, with no credentials when no password is configured, and can be repeated to keep the service down indefinitely. This issue is fixed in version 1.10.0.

CVSS v3
8.7
EG Score
8.7(medium)
EG Risk
70(Attend)
EG Risk 70/100SSVC: Attend

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
Severity87% × 45%
Exploitation40% × 40%
Automatability100% × 15%
Action: Remediate soon — notable exploitation risk.
EPSS PROB
0%
EPSS %ILE
36%
KEV
Not listed

Published

August 25, 2026

Last Modified

September 9, 2026

Advisory Details (2)

Auto-updated Aug 25, 2026
Patch available. Sources: github_commit, github.
github Patch Available

Unauthenticated remote process crash via malformed wire-protocol commands (missing bounds checks, no panic recovery) · Advisory · contribsys/faktory · GitHub

https://github.com/contribsys/faktory/security/advisories/GHSA-gc57-f6pg-m9h6
github_commit

commit c2f17e390fc7 (contribsys/faktory)

Fix landed in contribsys/faktory commit c2f17e390fc7 — awaiting tagged release

http://github.com/contribsys/faktory/commit/c2f17e390fc7d38b6ece82b8da23f5ca15646212

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 10× 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. 2026-09-19 02:17 UTCEG score recompute
  2. 2026-09-18 19:28 UTCEPSS rescore
  3. 2026-09-18 00:26 UTCEG score recompute
  4. 2026-09-16 22:39 UTCEG score recompute
  5. 2026-09-16 14:08 UTCEPSS rescore
  6. 2026-09-16 09:20 UTCEG score recompute
  7. 2026-09-16 05:15 UTCEPSS rescore
  8. 2026-09-15 06:08 UTCEG score recompute
  9. 2026-09-14 04:22 UTCEG score recompute
  10. 2026-09-13 02:36 UTCEG score recompute
  11. 2026-09-12 00:50 UTCEG score recompute
  12. 2026-09-11 14:53 UTCEPSS rescore
  13. 2026-09-11 11:57 UTCEG score recompute
  14. 2026-09-11 09:37 UTCEPSS rescore
  15. 2026-09-10 10:07 UTCEG score recompute
  16. 2026-09-09 00:56 UTCEG score recompute
  17. 2026-09-08 22:01 UTCEPSS rescore
  18. 2026-09-07 18:20 UTCEG score recompute
  19. 2026-09-07 16:01 UTCEPSS rescore
  20. 2026-09-06 16:22 UTCEG score recompute
  21. 2026-09-06 13:47 UTCEPSS rescore
  22. 2026-09-06 03:29 UTCEG score recompute
  23. 2026-09-05 15:31 UTCEPSS rescore
  24. 2026-09-05 01:43 UTCEG score recompute
  25. 2026-09-04 12:50 UTCEG score recompute
Show 21 more
  1. 2026-09-04 05:07 UTCEPSS rescore
  2. 2026-09-02 21:39 UTCEG score recompute
  3. 2026-09-02 14:12 UTCEPSS rescore
  4. 2026-09-01 19:48 UTCEG score recompute
  5. 2026-09-01 13:54 UTCEPSS rescore
  6. 2026-09-01 06:25 UTCEG score recompute
  7. 2026-09-01 04:40 UTCEPSS rescore
  8. 2026-08-31 03:38 UTCEG score recompute
  9. 2026-08-30 19:17 UTCEPSS rescore
  10. 2026-08-30 01:53 UTCEG score recompute
  11. 2026-08-30 01:22 UTCEPSS rescore
  12. 2026-08-29 00:02 UTCEG score recompute
  13. 2026-08-28 21:42 UTCEPSS rescore
  14. 2026-08-27 18:07 UTCEG score recompute
  15. 2026-08-27 14:25 UTCEPSS rescore
  16. 2026-08-26 15:56 UTCEG score recompute
  17. 2026-08-26 14:46 UTCEPSS rescore
  18. 2026-08-26 14:44 UTCEG score recompute
  19. 2026-08-25 22:29 UTCEG score recompute
  20. 2026-08-25 22:10 UTCEG score recompute
  21. 2026-08-25 22:09 UTCMITRE cvelistV5first tracked

Frequently asked(5)

What is CVE-2026-63403?
CVE-2026-63403 is a high vulnerability published on August 25, 2026. Faktory is a language-agnostic background job server. In versions prior to 1.10.0, the server is vulnerable to an unauthenticated denial of service in which a single malformed command crashes the entire process. Its wire protocol is line-based, and several command handlers slice or index the…
When was CVE-2026-63403 disclosed?
CVE-2026-63403 was first published in the National Vulnerability Database on August 25, 2026, with the most recent update on September 9, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-63403 actively exploited?
CVE-2026-63403 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 63.5% of all scored CVEs.
What is the CVSS score of CVE-2026-63403?
CVE-2026-63403 has a CVSS v3 base score of 8.7 (NVD).
How do I remediate CVE-2026-63403?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-63403, 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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