CVE-2026-4873

MEDIUMNVD 5.95.9—
EchelonGraph scoreMEDIUM confidence

Score 5.9 from GitHub Security Advisory published 2026-05-13. NVD baseline CVSS 5.9; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
Trending — 4 sources updated this week
5.9EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 5.9Exploit: None knownExposed: 0

A fix is available — apply it.

A vulnerability exists where a connection requiring TLS incorrectly reuses an existing unencrypted connection from the same connection pool. If an initial transfer is made in clear-text (via IMAP, SMTP, or POP3), a subsequent request to that same host bypasses the TLS requirement and instead transmit data unencrypted.

CVSS v3
5.9
EG Score
5.9(medium)
EG Risk
27(Track)
EG Risk 27/100SSVC: Track

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
Severity59% × 45%
Exploitation0% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
25%
KEV
Not listed

Published

May 13, 2026

Last Modified

May 14, 2026

Advisory Details (4)

Auto-updated May 14, 2026
⚠️ Active exploitation confirmed. No patch confirmed yet.
generic🔴 Active Exploitation

oss-security - [ADVISORY] curl: CVE-2026-4873: connection reuse ignores TLS requirement

http://www.openwall.com/lists/oss-security/2026/04/29/7
generic

HackerOne

https://hackerone.com/reports/3621851
generic
https://curl.se/docs/CVE-2026-4873.json
generic🔴 Active Exploitation

curl - connection reuse ignores TLS requirement - CVE-2026-4873

https://curl.se/docs/CVE-2026-4873.html

Vendor Advisories for CVE-2026-4873(2)

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

Patch Availability(2)

Vendor / EcosystemFixed in / PatchReleasedSource
ubuntulibcurl4t64 (8.18.0-1ubuntu2.1) @ resolute2026-08-23ubuntu
redhatcurl-main-8.20.0-0.1.hum12026-05-02redhat

Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.

Affected Packages

(6 across 6 ecosystems)
Alpine:v3.23(1)
PackageVulnerable rangeFixed inDependents
curl—8.20.0-r0—
Alpine:v3.24(1)
PackageVulnerable rangeFixed inDependents
curl—8.20.0-r0—
Debian:11(1)
PackageVulnerable rangeFixed inDependents
curl7.74.0-1.3 ... 8.9.1-2~bpo12+1 (219 versions)——
Debian:12(1)
PackageVulnerable rangeFixed inDependents
curl7.88.1-10 ... 8.9.1-2~bpo12+1 (174 versions)——
Debian:13(1)
PackageVulnerable rangeFixed inDependents
curl8.14.1-2, 8.14.1-2+deb13u1, 8.14.1-2+deb13u2, 8.14.1-2+deb13u2~bpo13+1, 8.14.1-2+deb13u38.14.1-2+deb13u4—
Debian:14(1)
PackageVulnerable rangeFixed inDependents
curl8.14.1-2 ... 8.20.0~rc1-1+exp3 (45 versions)8.20.0~rc2-1—

Weakness Classification(2)

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

Additional Vendor Advisories

(1)

Vendors that published advisories for this CVE beyond the curated set above. Broader coverage but minimal per-row detail — click through for the original advisory.

Data Freshness Timeline

(refreshed 9× in last 7d / 71× 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 206 total refreshes for this CVE.

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

Related CVEs(same vendor + same CWE)

Frequently asked(5)

What is CVE-2026-4873?
CVE-2026-4873 is a medium vulnerability published on May 13, 2026. A vulnerability exists where a connection requiring TLS incorrectly reuses an existing unencrypted connection from the same connection pool. If an initial transfer is made in clear-text (via IMAP, SMTP, or POP3), a subsequent request to that same host bypasses the TLS requirement and instead…
When was CVE-2026-4873 disclosed?
CVE-2026-4873 was first published in the National Vulnerability Database on May 13, 2026, with the most recent update on May 14, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-4873 actively exploited?
CVE-2026-4873 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 74.7% of all scored CVEs.
What is the CVSS score of CVE-2026-4873?
CVE-2026-4873 has a CVSS v3 base score of 5.9 (NVD).
How do I remediate CVE-2026-4873?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-4873, 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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