CVE-2026-63403

HIGHPre-NVD 8.78.7
EchelonGraph scoreMEDIUM confidence

“—” beside the score: it is equal to the CVSS score beside it.

This high-severity CVE scores 8.7 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.4% (36th percentile of EPSS-scored CVEs). No GitHub Security Advisory CVSS is on record for this CVE.

Triggered by: Headline CVSS from a secondary CVSS source
Sources: EPSS, a secondary CVSS source
Elevated
8.7EG
EchelonGraph verdictPlan a fixRemediate within your standard update timelines at low or medium mission impact and sooner than that at high (the SSVC decision on this page).
  • CISA's Vulnrichment rates exploitation as PoC; EchelonGraph holds no exploit-code reference for it
CISA-KEV: Not listedEPSS PROB: 0.4%CVSS: 8.7Exploit: No code on recordExposed services: Not assessed

The CVE record names the fixed release — apply it.

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
8.7HIGHmedium confidence
EG Risk
70
EG Risk 70/100

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 (value × EchelonGraph’s weight)
Severity87% × 45%
The EG Score, 8.7 of 10.
Exploitation40% × 40%
EchelonGraph's fixed weight for EG-KEV Tier 3 (Elevated): a constant, not a probability.
Automatability100% × 15%
CISA's SSVC Automatable value: yes (Vulnrichment).
SSVC (CISA's decision table, applied by EchelonGraph): Track at low or medium mission impact; Attend at high (mission-essential systems).
Exploitation public PoC (CISA Vulnrichment) · Automatable yes (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE.
Action: The CVE record names the fixed release. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.
EPSS PROB
0.4%
EPSS %ILE
36th
KEV
Not listed

SSVC (CISA's decision table, applied by EchelonGraph)Track at low or medium mission impact; Attend at high (mission-essential systems).

The CVE record names the fixed release. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.

Exploitation public PoC (CISA Vulnrichment) · Automatable yes (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE. Mission impact is CISA's Mission & Well-being decision point, and only you can judge it. CISA's table makes it high when Mission Prevalence is Essential — the vulnerable component "directly provides capabilities that constitute at least one MEF for at least one entity" (MEF: mission essential function) — or when Public Well-Being Impact is Irreversible: "multiple fatalities are likely", the cyber-physical system "is likely lost or destroyed", "extreme or serious externalities" are imposed on other parties, or social systems such as elections or the financial grid "are destabilized and potentially collapse". CISA's decision table

BOD 26-04 (CISA's remediation timeline, Table 1)14 days if the affected system is publicly exposed; 60 days if it is not.

In CISA KEV no (CISA's KEV catalog) · Automatable yes (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). Whether your system is publicly exposed is yours to answer. BOD 26-04 binds US Federal Civilian Executive Branch agencies; for anyone else it is CISA's published timeline, a reference rather than an obligation. The directive · how EchelonGraph applies it

Published

August 25, 2026

Last Modified

September 9, 2026

Advisory Details (2)

Auto-updated Aug 25, 2026
Fix named in the CVE record. Sources: github_commit, github.
GitHub advisoryMentions a patch (unverified)

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 16× in last 7d / 49× in last 30d)

Each row is a time one of our pipelines fetched, updated or re-scored this CVE. 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. An arrow marks a change the record states ("CVSS v3 → 9.1"); EPSS and GHSA rows show the values recorded at that time, not what changed (EPSS values are rounded; hover one for the exact figures). Most recent first.

  1. 2026-10-11 19:33 UTCEG score recompute
  2. 2026-10-11 16:48 UTCEG score recompute
  3. 2026-10-11 14:10 UTCEG score recompute
  4. 2026-10-11 13:49 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  5. 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  6. 2026-10-10 11:09 UTCEG score recompute
  7. 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  8. 2026-10-09 03:41 UTCEG score recompute
  9. 2026-10-08 17:13 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  10. 2026-10-08 02:17 UTCEG score recompute
  11. 2026-10-07 23:48 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  12. 2026-10-06 16:01 UTCEG score recompute
  13. 2026-10-06 15:18 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  14. 2026-10-06 01:51 UTCEG score recompute
  15. 2026-10-05 17:43 UTCEPSS rescoreEPSS 0.4% · 36th percentile
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  17. 2026-10-04 23:22 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  18. 2026-10-03 16:16 UTCEG score recompute
  19. 2026-10-03 14:26 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  20. 2026-10-03 01:45 UTCEG score recompute
  21. 2026-10-02 17:56 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  22. 2026-10-01 22:40 UTCEG score recompute
  23. 2026-10-01 19:50 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  24. 2026-09-30 20:09 UTCEG score recompute
  25. 2026-09-30 15:03 UTCEPSS rescoreEPSS 0.4% · 36th percentile
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  1. 2026-09-30 06:21 UTCEG score recompute
  2. 2026-09-29 01:35 UTCEG score recompute
  3. 2026-09-28 13:51 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  4. 2026-09-27 23:49 UTCEG score recompute
  5. 2026-09-26 21:32 UTCEG score recompute
  6. 2026-09-26 15:59 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  7. 2026-09-25 00:18 UTCEG score recompute
  8. 2026-09-23 22:14 UTCEG score recompute
  9. 2026-09-23 17:54 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  10. 2026-09-22 20:29 UTCEG score recompute
  11. 2026-09-22 07:35 UTCEG score recompute
  12. 2026-09-21 05:49 UTCEG score recompute
  13. 2026-09-20 20:16 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  14. 2026-09-20 04:04 UTCEG score recompute
  15. 2026-09-19 02:17 UTCEG score recompute
  16. 2026-09-18 19:28 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  17. 2026-09-18 00:26 UTCEG score recompute
  18. 2026-09-16 22:39 UTCEG score recompute
  19. 2026-09-16 14:08 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  20. 2026-09-16 09:20 UTCEG score recompute
  21. 2026-09-16 05:15 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  22. 2026-09-15 06:08 UTCEG score recompute
  23. 2026-09-14 04:22 UTCEG score recompute
  24. 2026-09-13 02:36 UTCEG score recompute
  25. 2026-09-12 00:50 UTCEG score recompute
  26. 2026-09-11 14:53 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  27. 2026-09-11 11:57 UTCEG score recompute
  28. 2026-09-11 09:37 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  29. 2026-09-10 10:07 UTCEG score recompute
  30. 2026-09-09 00:56 UTCEG score recompute
  31. 2026-09-08 22:01 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  32. 2026-09-07 18:20 UTCEG score recompute
  33. 2026-09-07 16:01 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  34. 2026-09-06 16:22 UTCEG score recompute
  35. 2026-09-06 13:47 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  36. 2026-09-06 03:29 UTCEG score recompute
  37. 2026-09-05 15:31 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  38. 2026-09-05 01:43 UTCEG score recompute
  39. 2026-09-04 12:50 UTCEG score recompute
  40. 2026-09-04 05:07 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  41. 2026-09-02 21:39 UTCEG score recompute
  42. 2026-09-02 14:12 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  43. 2026-09-01 19:48 UTCEG score recompute
  44. 2026-09-01 13:54 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  45. 2026-09-01 06:25 UTCEG score recompute
  46. 2026-09-01 04:40 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  47. 2026-08-31 03:38 UTCEG score recompute
  48. 2026-08-30 19:17 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  49. 2026-08-30 01:53 UTCEG score recompute
  50. 2026-08-30 01:22 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  51. 2026-08-29 00:02 UTCEG score recompute
  52. 2026-08-28 21:42 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  53. 2026-08-27 18:07 UTCEG score recompute
  54. 2026-08-27 14:25 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  55. 2026-08-26 15:56 UTCEG score recompute
  56. 2026-08-26 14:46 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  57. 2026-08-26 14:44 UTCEG score recompute
  58. 2026-08-25 22:29 UTCEG score recompute
  59. 2026-08-25 22:10 UTCEG score recomputeFirst assessed: 8.7 HIGH
  60. 2026-08-25 22:09 UTCMITRE cvelistV5first tracked

Frequently asked(5)

What is CVE-2026-63403?
CVE-2026-63403 is a high-severity vulnerability; its CVE record was 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 the CVE record for CVE-2026-63403 published?
The CVE record for CVE-2026-63403 was published on August 25, 2026. That is the record's publication date; the vulnerability itself may have been made public earlier. EchelonGraph's copy of the record carries a last-modified date of September 9, 2026; the record at its source may have been updated since.
Is CVE-2026-63403 actively exploited?
CVE-2026-63403 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.4% probability of exploitation in the next 30 days (36th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-63403?
CVE-2026-63403 has a CVSS base score of 8.7 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-63403?
The CVE record for CVE-2026-63403 names the fix: "This issue is fixed in version 1.10.0."

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