CVE-2026-73559

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: 0.6% (45th percentile of EPSS-scored CVEs). 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: 0.6%CVSS: 6.5Exploit: Elevated riskExposed services: Not assessed

A fix is available — apply it.

vLLM is an inference and serving engine for large language models. From 0.19.0 until 0.26.0, the /v1/completions CompletionRequest.prompt field in vllm/entrypoints/openai/completion/protocol.py accepts an unbounded list[str] or list[list[int]], prompt_to_seq() in vllm/renderers/inputs/preprocess.py and OnlineRenderer.preprocess_completion() in vllm/renderers/online_renderer.py expand every element, and vllm/entrypoints/openai/completion/serving.py creates one engine generator and response slot per prompt, allowing an authenticated API client to exhaust CPU, memory, async scheduling capacity, engine request slots, and response buffering with one request. This issue is fixed in version 0.26.0.

CVSS v3
6.5
EG Score
6.5MEDIUMmedium confidence
EG Risk
45
EG Risk 45/100CISA SSVC

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%
CISA SSVC: Track at low or medium mission impact; Track* at high (mission-essential systems).
Action: A fix is available. Apply it within your standard update timelines.
EPSS PROB
0.6%
EPSS %ILE
45th
KEV
Not listed

CISA SSVCTrack at low or medium mission impact; Track* at high (mission-essential systems).

A fix is available. Apply it within your standard update timelines.

Exploitation public PoC (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). Mission impact is CISA's Mission & Well-being decision point, and only you can judge it: high means the affected system is essential to your organisation's mission, or its compromise could cause irreversible harm to people. CISA's decision table

Published

August 13, 2026

Last Modified

September 28, 2026

Advisory Details (4)

Auto-updated Aug 13, 2026
Patch available. Sources: github_commit, github_release, github, github_pr.
github_release Patch Available

v0.26.0

Patch available: vllm-project/vllm v0.26.0

https://github.com/vllm-project/vllm/releases/tag/v0.26.0
github_commit

commit 675f4295cdfe (vllm-project/vllm)

Fix landed in vllm-project/vllm commit 675f4295cdfe — awaiting tagged release

https://github.com/vllm-project/vllm/commit/675f4295cdfe0d870471c2b51bfeca3a68a9569e
github_pr

fix(security): bound completion prompt list to prevent unbounded engine fan-out

Fix merged in vllm-project/vllm PR #47845 on 2026-07-07 — awaiting tagged release

https://github.com/vllm-project/vllm/pull/47845
github Patch Available

Completion prompt lists fan out into unbounded engine requests · Advisory · vllm-project/vllm · GitHub

https://github.com/vllm-project/vllm/security/advisories/GHSA-87x5-vmc3-756j

Vendor Advisories for CVE-2026-73559(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)
PyPI(1)
PackageVulnerable rangeFix by version rangeDependents
vllm0.19.0 ... 0.25.1 (12 versions)
  • 0.19.0 up to 0.26.0: fixed in 0.26.0
—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 8× in last 7d / 43× 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. 2026-10-04 23:22 UTCEPSS rescore
  2. 2026-10-03 19:48 UTCEG score recompute
  3. 2026-10-03 14:26 UTCEPSS rescore
  4. 2026-10-02 07:33 UTCEG score recompute
  5. 2026-10-01 19:50 UTCEPSS rescore
  6. 2026-09-30 21:47 UTCEG score recompute
  7. 2026-09-29 15:24 UTCEPSS rescore
  8. 2026-09-28 18:56 UTCEG score recompute
  9. 2026-09-28 13:52 UTCEPSS rescore
  10. 2026-09-28 07:36 UTCEG score recompute
  11. 2026-09-27 13:48 UTCEPSS rescore
  12. 2026-09-27 09:44 UTCEG score recompute
  13. 2026-09-26 15:59 UTCEPSS rescore
  14. 2026-09-25 03:33 UTCEG score recompute
  15. 2026-09-23 20:49 UTCEG score recompute
  16. 2026-09-23 17:54 UTCEPSS rescore
  17. 2026-09-22 21:00 UTCEG score recompute
  18. 2026-09-21 21:09 UTCEPSS rescore
  19. 2026-09-20 21:11 UTCEG score recompute
  20. 2026-09-20 20:16 UTCEPSS rescore
  21. 2026-09-19 23:10 UTCEG score recompute
  22. 2026-09-19 00:41 UTCEG score recompute
  23. 2026-09-18 19:28 UTCEPSS rescore
  24. 2026-09-18 02:48 UTCEG score recompute
  25. 2026-09-17 04:56 UTCEG score recompute
Show 65 more
  1. 2026-09-16 14:08 UTCEPSS rescore
  2. 2026-09-16 07:03 UTCEG score recompute
  3. 2026-09-16 05:15 UTCEPSS rescore
  4. 2026-09-15 09:10 UTCEG score recompute
  5. 2026-09-15 03:12 UTCEPSS rescore
  6. 2026-09-14 11:18 UTCEG score recompute
  7. 2026-09-12 15:34 UTCEG score recompute
  8. 2026-09-12 15:02 UTCEPSS rescore
  9. 2026-09-11 17:42 UTCEG score recompute
  10. 2026-09-11 14:53 UTCEPSS rescore
  11. 2026-09-10 19:31 UTCEG score recompute
  12. 2026-09-10 09:35 UTCEPSS rescore
  13. 2026-09-09 04:57 UTCEG score recompute
  14. 2026-09-08 22:01 UTCEPSS rescore
  15. 2026-09-07 18:12 UTCEG score recompute
  16. 2026-09-06 20:20 UTCEG score recompute
  17. 2026-09-06 13:48 UTCEPSS rescore
  18. 2026-09-05 22:25 UTCEG score recompute
  19. 2026-09-05 00:30 UTCEG score recompute
  20. 2026-09-04 05:07 UTCEPSS rescore
  21. 2026-09-02 23:11 UTCEG score recompute
  22. 2026-09-02 14:12 UTCEPSS rescore
  23. 2026-09-01 23:47 UTCEG score recompute
  24. 2026-09-01 13:54 UTCEPSS rescore
  25. 2026-09-01 04:40 UTCEPSS rescore
  26. 2026-09-01 04:40 UTCEPSS rescore
  27. 2026-08-31 03:46 UTCEG score recompute
  28. 2026-08-30 19:18 UTCEPSS rescore
  29. 2026-08-30 19:17 UTCEPSS rescore
  30. 2026-08-30 05:55 UTCEG score recompute
  31. 2026-08-30 01:22 UTCEPSS rescore
  32. 2026-08-29 08:02 UTCEG score recompute
  33. 2026-08-28 21:42 UTCEPSS rescore
  34. 2026-08-28 10:08 UTCEG score recompute
  35. 2026-08-27 14:25 UTCEPSS rescore
  36. 2026-08-27 11:53 UTCEG score recompute
  37. 2026-08-26 14:47 UTCEPSS rescore
  38. 2026-08-25 16:08 UTCEG score recompute
  39. 2026-08-25 13:49 UTCEPSS rescore
  40. 2026-08-24 18:14 UTCEG score recompute
  41. 2026-08-23 20:22 UTCEG score recompute
  42. 2026-08-23 00:19 UTCEPSS rescore
  43. 2026-08-22 00:37 UTCEG score recompute
  44. 2026-08-21 23:49 UTCEPSS rescore
  45. 2026-08-21 02:44 UTCEG score recompute
  46. 2026-08-20 22:56 UTCEPSS rescore
  47. 2026-08-20 04:52 UTCEG score recompute
  48. 2026-08-19 17:04 UTCEPSS rescore
  49. 2026-08-19 06:59 UTCEG score recompute
  50. 2026-08-18 13:49 UTCEPSS rescore
  51. 2026-08-18 13:49 UTCEPSS rescore
  52. 2026-08-18 09:06 UTCEG score recompute
  53. 2026-08-17 13:47 UTCEPSS rescore
  54. 2026-08-17 11:10 UTCEG score recompute
  55. 2026-08-16 14:56 UTCEPSS rescore
  56. 2026-08-16 14:56 UTCEPSS rescore
  57. 2026-08-16 13:18 UTCEG score recompute
  58. 2026-08-16 02:15 UTCEPSS rescore
  59. 2026-08-15 15:26 UTCEG score recompute
  60. 2026-08-15 01:31 UTCEPSS rescore
  61. 2026-08-14 17:34 UTCEG score recompute
  62. 2026-08-14 17:07 UTCEG score recompute
  63. 2026-08-13 16:25 UTCEG score recompute
  64. 2026-08-13 15:32 UTCEG score recompute
  65. 2026-08-13 15:31 UTCMITRE cvelistV5first tracked

Related CVEs(same product + same CWE)

Frequently asked(5)

What is CVE-2026-73559?
CVE-2026-73559 is a medium vulnerability published on August 13, 2026. vLLM is an inference and serving engine for large language models. From 0.19.0 until 0.26.0, the /v1/completions CompletionRequest.prompt field in vllm/entrypoints/openai/completion/protocol.py accepts an unbounded list[str] or list[list[int]], prompttoseq() in vllm/renderers/inputs/preprocess.py…
When was CVE-2026-73559 disclosed?
CVE-2026-73559 was first published on August 13, 2026, with the most recent update on September 28, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-73559 actively exploited?
CVE-2026-73559 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.6% probability of exploitation in the next 30 days (45th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-73559?
CVE-2026-73559 has a CVSS base score of 6.5 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-73559?
A fix for CVE-2026-73559 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-73559 are linked in the Vendor Advisories panel on this page.

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