CVE-2026-33603

MEDIUMNVD 6.86.8—
EchelonGraph scoreMEDIUM confidence

Score 6.8 from GitHub Security Advisory published 2026-05-12. NVD baseline CVSS 6.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
6.8EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 6.8Exploit: None knownExposed: 0

A fix is available — apply it.

Attacker can use a specially crafted base64 exchange between Dovecot and Client to fake SCRAM TLS channel binding. This requires that the attacker is able to position itself between Dovecot and the client connection. If successful, the attacker can eavesdrop communications between Dovecot and client as MITM proxy. Install fixed version. No publicly available exploits are known.

CVSS v3
6.8
EG Score
6.8(medium)
EG Risk
31(Track)
EG Risk 31/100SSVC: 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
Severity68% × 45%
Exploitation0% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
12%
KEV
Not listed

Published

May 12, 2026

Last Modified

May 18, 2026

Advisory Details (1)

Auto-updated May 18, 2026
No patch confirmed yet.
generic
https://documentation.open-xchange.com/dovecot/security/advisories/csaf/2026/oxdc-adv-2026-0002.json

Patch Availability(1)

Vendor / EcosystemFixed in / PatchReleasedSource
ubuntudovecot-submissiond (1:2.4.1+dfsg1-5ubuntu4.2) @ questing2026-08-23ubuntu

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
dovecot—2.4.4-r0—
Alpine:v3.24(1)
PackageVulnerable rangeFixed inDependents
dovecot—2.4.4-r0—
Debian:11(1)
PackageVulnerable rangeFixed inDependents
dovecot1:2.3.13+dfsg1-2, 1:2.3.13+dfsg1-2+deb11u1, 1:2.3.13+dfsg1-2+deb11u2, 1:2.3.13+dfsg1-2+deb11u31:2.3.13+dfsg1-2+deb11u4—
Debian:12(1)
PackageVulnerable rangeFixed inDependents
dovecot1:2.3.19.1+dfsg1-2.1 ... 1:2.3.19.1+dfsg1-2.1+deb12u5 (6 versions)1:2.3.19.1+dfsg1-2.1+deb12u6—
Debian:13(1)
PackageVulnerable rangeFixed inDependents
dovecot1:2.4.1+dfsg1-6 ... 1:2.4.1+dfsg1-6+deb13u5 (6 versions)1:2.4.1+dfsg1-6+deb13u6—
Debian:14(1)
PackageVulnerable rangeFixed inDependents
dovecot1:2.4.1+dfsg1-6 ... 1:2.4.3+dfsg1-2 (10 versions)1:2.4.4+dfsg1-1—

Weakness Classification(1)

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

All Vendor Advisories

(1)

Every vendor that published an advisory referencing this CVE — pulled from our cve_vendor_advisories aggregation. Click any row for the vendor's original advisory page.

Data Freshness Timeline

(refreshed 8× in last 7d / 34× 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 241 total refreshes for this CVE.

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

Frequently asked(5)

What is CVE-2026-33603?
CVE-2026-33603 is a medium vulnerability published on May 12, 2026. Attacker can use a specially crafted base64 exchange between Dovecot and Client to fake SCRAM TLS channel binding. This requires that the attacker is able to position itself between Dovecot and the client connection. If successful, the attacker can eavesdrop communications between Dovecot and…
When was CVE-2026-33603 disclosed?
CVE-2026-33603 was first published in the National Vulnerability Database on May 12, 2026, with the most recent update on May 18, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-33603 actively exploited?
CVE-2026-33603 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 88.0% of all scored CVEs.
What is the CVSS score of CVE-2026-33603?
CVE-2026-33603 has a CVSS v3 base score of 6.8 (NVD).
How do I remediate CVE-2026-33603?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-33603, 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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