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 / 36× 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 236 total refreshes for this CVE.

  1. 2026-09-15 03:11 UTCEPSS rescore
  2. 2026-09-13 16:47 UTCEPSS rescore
  3. 2026-09-12 15:01 UTCEPSS rescore
  4. 2026-09-11 14:53 UTCEPSS rescore
  5. 2026-09-11 11:23 UTCOSV refresh
  6. 2026-09-11 09:37 UTCEPSS rescore
  7. 2026-09-10 09:34 UTCEPSS rescore
  8. 2026-09-08 22:00 UTCEPSS rescore
  9. 2026-09-07 16:01 UTCEPSS rescore
  10. 2026-09-06 13:47 UTCEPSS rescore
  11. 2026-09-06 13:47 UTCEPSS rescore
  12. 2026-09-04 05:06 UTCEPSS rescore
  13. 2026-09-02 14:11 UTCEPSS rescore
  14. 2026-09-01 13:53 UTCEPSS rescore
  15. 2026-09-01 04:39 UTCEPSS rescore
  16. 2026-09-01 04:39 UTCEPSS rescore
  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. 2026-08-24 14:17 UTCEPSS rescore
  24. 2026-08-23 18:28 UTCEG score recompute
  25. 2026-08-23 18:28 UTCVendor advisory
Show 75 more
  1. 2026-08-23 18:28 UTCGHSA enrichment
  2. 2026-08-23 00:19 UTCEPSS rescore
  3. 2026-08-20 22:55 UTCEPSS rescore
  4. 2026-08-20 22:55 UTCEPSS rescore
  5. 2026-08-19 17:03 UTCEPSS rescore
  6. 2026-08-18 13:48 UTCEPSS rescore
  7. 2026-08-17 13:47 UTCEPSS rescore
  8. 2026-08-17 10:56 UTCEG score recompute
  9. 2026-08-17 10:56 UTCVendor advisory
  10. 2026-08-17 10:56 UTCGHSA enrichment
  11. 2026-08-16 14:56 UTCEPSS rescore
  12. 2026-08-16 04:18 UTCEG score recompute
  13. 2026-08-16 04:18 UTCVendor advisory
  14. 2026-08-16 04:18 UTCGHSA enrichment
  15. 2026-08-16 02:14 UTCEPSS rescore
  16. 2026-08-15 01:30 UTCEPSS rescore
  17. 2026-08-15 01:28 UTCVendor advisory
  18. 2026-08-15 01:28 UTCGHSA enrichment
  19. 2026-08-14 02:49 UTCEG score recompute
  20. 2026-08-14 02:49 UTCVendor advisory
  21. 2026-08-14 02:49 UTCGHSA enrichment
  22. 2026-08-13 22:00 UTCEPSS rescore
  23. 2026-08-12 22:25 UTCEG score recompute
  24. 2026-08-12 22:25 UTCVendor advisory
  25. 2026-08-12 22:25 UTCGHSA enrichment
  26. 2026-08-12 13:50 UTCEPSS rescore
  27. 2026-08-11 23:46 UTCEG score recompute
  28. 2026-08-11 23:46 UTCVendor advisory
  29. 2026-08-11 23:45 UTCGHSA enrichment
  30. 2026-08-11 01:06 UTCEG score recompute
  31. 2026-08-11 01:06 UTCVendor advisory
  32. 2026-08-11 01:06 UTCGHSA enrichment
  33. 2026-08-11 00:00 UTCEPSS rescore
  34. 2026-08-10 00:48 UTCEG score recompute
  35. 2026-08-10 00:48 UTCVendor advisory
  36. 2026-08-10 00:48 UTCGHSA enrichment
  37. 2026-08-09 13:46 UTCEPSS rescore
  38. 2026-08-09 02:08 UTCEG score recompute
  39. 2026-08-09 02:08 UTCVendor advisory
  40. 2026-08-09 02:08 UTCGHSA enrichment
  41. 2026-08-08 16:37 UTCEPSS rescore
  42. 2026-08-07 19:12 UTCEG score recompute
  43. 2026-08-07 19:12 UTCVendor advisory
  44. 2026-08-07 19:12 UTCGHSA enrichment
  45. 2026-08-06 20:32 UTCEG score recompute
  46. 2026-08-06 20:32 UTCVendor advisory
  47. 2026-08-06 20:32 UTCGHSA enrichment
  48. 2026-08-06 13:46 UTCEPSS rescore
  49. 2026-08-05 21:52 UTCEG score recompute
  50. 2026-08-05 21:52 UTCVendor advisory
  51. 2026-08-05 21:52 UTCGHSA enrichment
  52. 2026-08-05 19:17 UTCEPSS rescore
  53. 2026-08-04 15:10 UTCEPSS rescore
  54. 2026-08-04 10:38 UTCEPSS rescore
  55. 2026-08-03 20:58 UTCVendor advisory
  56. 2026-08-03 20:58 UTCGHSA enrichment
  57. 2026-08-02 22:18 UTCEG score recompute
  58. 2026-08-02 22:18 UTCVendor advisory
  59. 2026-08-02 22:18 UTCGHSA enrichment
  60. 2026-08-02 02:27 UTCEPSS rescore
  61. 2026-08-01 23:38 UTCEG score recompute
  62. 2026-08-01 23:38 UTCVendor advisory
  63. 2026-08-01 23:38 UTCGHSA enrichment
  64. 2026-08-01 04:16 UTCEPSS rescore
  65. 2026-07-30 16:28 UTCEPSS rescore
  66. 2026-07-30 01:30 UTCEPSS rescore
  67. 2026-07-27 14:13 UTCEPSS rescore
  68. 2026-07-26 14:54 UTCEPSS rescore
  69. 2026-07-26 14:54 UTCEPSS rescore
  70. 2026-07-25 14:18 UTCEPSS rescore
  71. 2026-07-25 14:18 UTCEPSS rescore
  72. 2026-07-24 14:17 UTCEPSS rescore
  73. 2026-07-24 14:17 UTCEPSS rescore
  74. 2026-07-23 14:18 UTCEPSS rescore
  75. 2026-07-23 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 88.2% 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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