CVE-2026-40560

HIGHNVD 7.57.5—
EchelonGraph scoreMEDIUM confidence

Score 7.5 from GitHub Security Advisory (severity: HIGH) published 2026-04-29. NVD baseline CVSS 7.5; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
7.5
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: 0%CVSS: 7.5Exploit: NoneExposed: 0

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

Starman versions before 0.4018 for Perl allows HTTP Request Smuggling via Improper Header Precedence.

Starman incorrectly prioritizes "Content-Length" over "Transfer-Encoding: chunked" when both headers are present in an HTTP request. Per RFC 7230 3.3.3, Transfer-Encoding must take precedence.

An attacker could exploit this to smuggle malicious HTTP requests via a front-end reverse proxy.

CVSS v3
7.5
EG Score
7.5(medium)
EPSS
38.7%
KEV
Not listed

Published

April 29, 2026

Last Modified

May 6, 2026

Advisory Details (4)

Auto-updated Apr 29, 2026
No patch confirmed yet.
generic

oss-security - CVE-2026-40560: Starman versions before 0.4018 for Perl allows HTTP Request Smuggling via Improper Header Precedence

http://www.openwall.com/lists/oss-security/2026/04/29/1
generic

Changes - metacpan.org

https://metacpan.org/release/MIYAGAWA/Starman-0.4018/changes
generic
https://github.com/miyagawa/Starman/commit/ced205f0805027e9d9c0731f8c40b104220604ed.patch
generic

RFC 7230 - Hypertext Transfer Protocol (HTTP/1.1): Message Syntax and Routing

https://datatracker.ietf.org/doc/html/rfc7230#section-3.3.3

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 9× in last 7d / 37× 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.

Showing the most recent 100 of 132 total refreshes for this CVE.

  1. 2026-07-15 16:57 UTCEPSS rescore
  2. 2026-07-15 16:57 UTCEPSS rescore
  3. 2026-07-15 02:00 UTCEPSS rescore
  4. 2026-07-13 22:30 UTCEPSS rescore
  5. 2026-07-13 06:13 UTCEPSS rescore
  6. 2026-07-13 06:13 UTCEPSS rescore
  7. 2026-07-12 05:46 UTCEPSS rescore
  8. 2026-07-11 08:27 UTCEPSS rescore
  9. 2026-07-09 19:10 UTCEPSS rescore
  10. 2026-07-08 15:15 UTCEPSS rescore
  11. 2026-07-07 13:46 UTCEPSS rescore
  12. 2026-07-06 16:27 UTCEPSS rescore
  13. 2026-07-06 16:27 UTCEPSS rescore
  14. 2026-07-06 02:23 UTCEPSS rescore
  15. 2026-07-06 02:23 UTCEPSS rescore
  16. 2026-07-05 02:30 UTCEPSS rescore
  17. 2026-07-04 06:31 UTCEPSS rescore
  18. 2026-07-01 15:06 UTCEPSS rescore
  19. 2026-06-30 23:22 UTCEPSS rescore
  20. 2026-06-29 14:06 UTCEPSS rescore
  21. 2026-06-28 14:07 UTCEPSS rescore
  22. 2026-06-28 04:56 UTCEPSS rescore
  23. 2026-06-27 03:08 UTCEPSS rescore
  24. 2026-06-25 13:49 UTCEPSS rescore
  25. 2026-06-25 13:49 UTCEPSS rescore
Show 75 more
  1. 2026-06-24 14:05 UTCEPSS rescore
  2. 2026-06-23 21:33 UTCEPSS rescore
  3. 2026-06-22 14:25 UTCEPSS rescore
  4. 2026-06-22 14:25 UTCEPSS rescore
  5. 2026-06-21 14:56 UTCEPSS rescore
  6. 2026-06-21 14:56 UTCEPSS rescore
  7. 2026-06-21 01:59 UTCEPSS rescore
  8. 2026-06-19 19:25 UTCEPSS rescore
  9. 2026-06-18 17:52 UTCEPSS rescore
  10. 2026-06-18 17:52 UTCEPSS rescore
  11. 2026-06-17 17:53 UTCEPSS rescore
  12. 2026-06-16 17:52 UTCEPSS rescore
  13. 2026-06-15 17:49 UTCEPSS rescore
  14. 2026-06-14 20:50 UTCEG score recompute
  15. 2026-06-14 20:49 UTCGHSA enrichment
  16. 2026-06-14 09:30 UTCEG score recompute
  17. 2026-06-14 09:30 UTCGHSA enrichment
  18. 2026-06-13 23:00 UTCEPSS rescore
  19. 2026-06-12 23:12 UTCEPSS rescore
  20. 2026-06-12 23:12 UTCEPSS rescore
  21. 2026-06-12 04:49 UTCEG score recompute
  22. 2026-06-12 04:49 UTCGHSA enrichment
  23. 2026-06-11 17:28 UTCEG score recompute
  24. 2026-06-11 17:28 UTCGHSA enrichment
  25. 2026-06-11 14:00 UTCEPSS rescore
  26. 2026-06-11 05:44 UTCEG score recompute
  27. 2026-06-11 05:44 UTCGHSA enrichment
  28. 2026-06-10 22:18 UTCEPSS rescore
  29. 2026-06-10 13:22 UTCEPSS rescore
  30. 2026-06-10 13:22 UTCEPSS rescore
  31. 2026-06-10 12:54 UTCEG score recompute
  32. 2026-06-10 12:54 UTCGHSA enrichment
  33. 2026-06-10 01:35 UTCEG score recompute
  34. 2026-06-10 01:35 UTCGHSA enrichment
  35. 2026-06-09 14:16 UTCEG score recompute
  36. 2026-06-09 14:16 UTCGHSA enrichment
  37. 2026-06-09 02:57 UTCEG score recompute
  38. 2026-06-09 02:57 UTCGHSA enrichment
  39. 2026-06-08 14:17 UTCEPSS rescore
  40. 2026-06-08 14:17 UTCEPSS rescore
  41. 2026-06-08 13:51 UTCEG score recompute
  42. 2026-06-08 13:51 UTCGHSA enrichment
  43. 2026-06-08 02:31 UTCEG score recompute
  44. 2026-06-08 02:31 UTCGHSA enrichment
  45. 2026-06-07 15:25 UTCEPSS rescore
  46. 2026-06-07 15:25 UTCEPSS rescore
  47. 2026-06-07 15:12 UTCEG score recompute
  48. 2026-06-07 15:12 UTCGHSA enrichment
  49. 2026-06-07 03:53 UTCEG score recompute
  50. 2026-06-07 03:53 UTCGHSA enrichment
  51. 2026-06-06 16:29 UTCEG score recompute
  52. 2026-06-06 16:29 UTCGHSA enrichment
  53. 2026-06-06 13:47 UTCEPSS rescore
  54. 2026-06-06 13:47 UTCEPSS rescore
  55. 2026-06-06 04:59 UTCEG score recompute
  56. 2026-06-06 04:59 UTCGHSA enrichment
  57. 2026-06-05 22:47 UTCEPSS rescore
  58. 2026-06-05 17:35 UTCEG score recompute
  59. 2026-06-05 17:35 UTCGHSA enrichment
  60. 2026-06-05 06:12 UTCEG score recompute
  61. 2026-06-05 06:12 UTCGHSA enrichment
  62. 2026-06-05 06:10 UTCEPSS rescore
  63. 2026-06-05 06:10 UTCEPSS rescore
  64. 2026-06-04 18:50 UTCEG score recompute
  65. 2026-06-04 18:50 UTCGHSA enrichment
  66. 2026-06-04 13:12 UTCEPSS rescore
  67. 2026-06-04 13:12 UTCEPSS rescore
  68. 2026-06-04 07:31 UTCEG score recompute
  69. 2026-06-04 07:31 UTCGHSA enrichment
  70. 2026-06-03 19:54 UTCEG score recompute
  71. 2026-06-03 19:54 UTCGHSA enrichment
  72. 2026-06-03 08:32 UTCEG score recompute
  73. 2026-06-03 08:32 UTCGHSA enrichment
  74. 2026-06-02 21:04 UTCEG score recompute
  75. 2026-06-02 21:04 UTCGHSA enrichment

Frequently asked(5)

What is CVE-2026-40560?
CVE-2026-40560 is a high vulnerability published on April 29, 2026. Starman versions before 0.4018 for Perl allows HTTP Request Smuggling via Improper Header Precedence. Starman incorrectly prioritizes "Content-Length" over "Transfer-Encoding: chunked" when both headers are present in an HTTP request. Per RFC 7230 3.3.3, Transfer-Encoding must take precedence. An…
When was CVE-2026-40560 disclosed?
CVE-2026-40560 was first published in the National Vulnerability Database on April 29, 2026, with the most recent update on May 6, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-40560 actively exploited?
CVE-2026-40560 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 38.7% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-40560?
CVE-2026-40560 has a CVSS v3 base score of 7.5 (NVD).
How do I remediate CVE-2026-40560?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-40560, 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.

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