CVE-2026-54388

CRITICALPre-NVD 9.19.1—
EchelonGraph scoreMEDIUM confidence

Score 9.1 from GitHub Security Advisory (severity: CRITICAL) published 2026-06-17. a secondary CVSS source baseline 9.1; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
Elevated
9.1EG
EchelonGraph verdictPlan mitigationSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0.7%CVSS: 9.1Exploit: Elevated riskExposed services: Not assessed

An upstream fix is merged but not yet released — mitigate (WAF / firewall / segmentation) until the release ships, then apply it.

Tinyproxy through 1.11.3, fixed in commit 364cdb6, fails to reject requests containing multiple Content-Length headers with differing values, forwarding all duplicate headers to the backend while using the first value to determine how many request body bytes to consume. Remote attackers can desynchronize the proxy and backend parser state, allowing injection of arbitrary HTTP requests to the backend to enable cache poisoning, access control bypass, and request hijacking.

CVSS v3
9.1
EG Score
9.1CRITICALmedium confidence
EG Risk
72
EG Risk 72/100

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
Severity91% × 45%
Exploitation40% × 40%
Automatability100% × 15%
EPSS PROB
0.7%
EPSS %ILE
50th
KEV
Not listed

Published

June 17, 2026

Last Modified

July 14, 2026

Advisory Details (4)

Auto-updated Sep 16, 2026
Upstream fix merged — awaiting tagged release. Sources: github_commit, github_pr.
generic

HTTP Request Smuggling: CL/TE desync + duplicate Content-Length forwarding · Issue #609 · tinyproxy/tinyproxy · GitHub

https://github.com/tinyproxy/tinyproxy/issues/609
generic

Tinyproxy - HTTP Request Smuggling via Duplicate Content-Length Headers | Advisories | VulnCheck

https://www.vulncheck.com/advisories/tinyproxy-http-request-smuggling-via-duplicate-content-length-headers
github_pr

Prevent request smuggling

Fix merged in tinyproxy/tinyproxy PR #610 on 2026-05-07 — awaiting tagged release

https://github.com/tinyproxy/tinyproxy/pull/610
github_commit

commit 364cdb67e0ea (tinyproxy/tinyproxy)

Fix landed in tinyproxy/tinyproxy commit 364cdb67e0ea — awaiting tagged release

https://github.com/tinyproxy/tinyproxy/commit/364cdb67e0ea00a8e4a7037e2693e0711e816adb

Vendor Advisories for CVE-2026-54388(1)

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

Affected Packages

(2 across 2 ecosystems)
Debian:11(1)
PackageVulnerable rangeFix by version rangeDependents
tinyproxy1.10.0-5 ... 1.11.3-1~bpo13+1 (15 versions)
  • every version on: no fix on record
—
Debian:14(1)
PackageVulnerable rangeFix by version rangeDependents
tinyproxy1.11.2-1, 1.11.3-1, 1.11.3-1~bpo13+1
  • every version on: no fix on record
—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 7× in last 7d / 30× 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 468 total refreshes for this CVE.

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

Related CVEs(same product + same CWE)

Frequently asked(5)

What is CVE-2026-54388?
CVE-2026-54388 is a critical vulnerability published on June 17, 2026. Tinyproxy through 1.11.3, fixed in commit 364cdb6, fails to reject requests containing multiple Content-Length headers with differing values, forwarding all duplicate headers to the backend while using the first value to determine how many request body bytes to consume. Remote attackers can…
When was CVE-2026-54388 disclosed?
CVE-2026-54388 was first published on June 17, 2026, with the most recent update on July 14, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-54388 actively exploited?
CVE-2026-54388 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.7% probability of exploitation in the next 30 days (50th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-54388?
CVE-2026-54388 has a CVSS base score of 9.1 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-54388?
An upstream fix for CVE-2026-54388 has been merged but is not yet in a tagged release. Until it ships, restrict network exposure of the affected system or apply the vendor's mitigation, then update to the release that contains the fix. The vendor advisories EchelonGraph has for CVE-2026-54388 are linked in the Vendor Advisories panel on this page.

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