CVE-2026-33263

MEDIUMPre-NVD 4.34.3
EchelonGraph scoreMEDIUM confidence

“—” beside the score: it is equal to the CVSS score beside it.

Score 4.3 from GitHub Security Advisory published 2026-08-28. A secondary CVSS source baseline 4.3; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: EPSS, GitHub Security Advisory, a secondary CVSS source
Trending — Patch released this week
4.3EG
EchelonGraph verdictMonitorRemediate within your standard update timelines (the SSVC decision on this page).
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0.6%CVSS: 4.3Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

When mail_max_userip_connections is set (default 10) and reached, submission-login can crash with epoll() panic caused by file descriptor handling issues. If running in high-security mode (default for community releases), only the new submission connection gets terminated. If running in high-performance mode (default for Pro releases), all connections handled by the submission-login process will be terminated. The crashes can cause failure for user to send a message, or it can cause duplicate messages to be sent. If TLS is not used (in the backend server processing the submission), duplicate deliveries cannot happen, because the crash can only happen at AUTH stage. Limit the number of connections handled by single submission-login process. This has a performance impact though. Update to non-vulnerable version. No publicly available exploits are known.

CVSS v3
4.3
EG Score
4.3MEDIUMmedium confidence
EG Risk
20
EG Risk 20/100

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 (value × EchelonGraph’s weight)
Severity43% × 45%
The EG Score, 4.3 of 10.
Exploitation0.5% × 40%
FIRST EPSS: the 30-day exploitation probability when EchelonGraph scored this CVE.
Automatability0% × 15%
CISA's SSVC Automatable value: no (Vulnrichment).
SSVC (CISA's decision table, applied by EchelonGraph): Track at every mission impact level.
Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE.
Action: A fix is available. Apply it within your standard update timelines.
EPSS PROB
0.6%
EPSS %ILE
44th
KEV
Not listed

SSVC (CISA's decision table, applied by EchelonGraph)Track at every mission impact level.

A fix is available. Apply it within your standard update timelines.

Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE. Mission impact is CISA's Mission & Well-being decision point, and only you can judge it. CISA's table makes it high when Mission Prevalence is Essential — the vulnerable component "directly provides capabilities that constitute at least one MEF for at least one entity" (MEF: mission essential function) — or when Public Well-Being Impact is Irreversible: "multiple fatalities are likely", the cyber-physical system "is likely lost or destroyed", "extreme or serious externalities" are imposed on other parties, or social systems such as elections or the financial grid "are destabilized and potentially collapse". CISA's decision table

BOD 26-04 (CISA's remediation timeline, Table 1)60 days if the affected system is publicly exposed; Fix on system upgrade if it is not.

In CISA KEV no (CISA's KEV catalog) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). Whether your system is publicly exposed is yours to answer. BOD 26-04 binds US Federal Civilian Executive Branch agencies; for anyone else it is CISA's published timeline, a reference rather than an obligation. The directive · how EchelonGraph applies it

Published

August 28, 2026

Last Modified

September 3, 2026

Advisory Details (1)

Auto-updated Aug 28, 2026
Patch available.
Web page
https://documentation.open-xchange.com/dovecot/security/advisories/csaf/2026/oxdc-adv-2026-0003.json

Vendor Advisories for CVE-2026-33263(4)

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 / EcosystemFix (by version range) / PatchReleasedSource
redhatdovecot-1:2.3.21-19.el10_2.82026-10-08redhat
redhatdovecot-1:2.3.16-16.el8_102026-10-06redhat

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

(5 across 5 ecosystems)
Alpine:v3.23(1)
PackageVulnerable rangeFix by version rangeDependents
dovecot—
  • every version up to 2.4.5-r0: fixed in 2.4.5-r0
—
Alpine:v3.24(1)
PackageVulnerable rangeFix by version rangeDependents
dovecot—
  • every version up to 2.4.5-r0: fixed in 2.4.5-r0
—
Debian:12(1)
PackageVulnerable rangeFix by version rangeDependents
dovecot1:2.3.19.1+dfsg1-2.1 ... 1:2.4.5+dfsg1-3 (43 versions)
  • every version on: no fix on record
—
Debian:13(1)
PackageVulnerable rangeFix by version rangeDependents
dovecot1:2.4.1+dfsg1-6 ... 1:2.4.1+dfsg1-6+deb13u6 (7 versions)
  • every version up to 1:2.4.1+dfsg1-6+deb13u7: fixed in 1:2.4.1+dfsg1-6+deb13u7
—
Debian:14(1)
PackageVulnerable rangeFix by version rangeDependents
dovecot1:2.4.1+dfsg1-6 ... 1:2.4.4+dfsg1-2 (12 versions)
  • every version up to 1:2.4.5+dfsg1-1: fixed in 1:2.4.5+dfsg1-1
—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 20× in last 7d / 80× in last 30d)

Each row is a time one of our pipelines fetched, updated or re-scored this CVE. 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. An arrow marks a change the record states ("CVSS v3 → 9.1"); EPSS and GHSA rows show the values recorded at that time, not what changed (EPSS values are rounded; hover one for the exact figures). Most recent first.

Showing the most recent 99 of 134 refreshes on record for this CVE.

A repeat, a row identical to one the same pipeline wrote less than 10 seconds earlier, is not a separate refresh and is not counted. 1 repeat row among the latest 100 is merged into the row it repeats. The 35 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-10-13 16:34 UTCEPSS rescoreEPSS 0.6% · 44th percentile
  2. 2026-10-12 16:34 UTCEPSS rescoreEPSS 0.6% · 44th percentile
  3. 2026-10-12 16:13 UTCEG score recompute
  4. 2026-10-11 19:55 UTCEG score recompute
  5. 2026-10-11 17:09 UTCEG score recompute
  6. 2026-10-11 14:36 UTCEG score recompute
  7. 2026-10-11 13:48 UTCEPSS rescoreEPSS 0.6% · 44th percentile
  8. 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.6% · 44th percentile
  9. 2026-10-10 00:59 UTCEG score recompute
  10. 2026-10-10 00:59 UTCVendor advisory
  11. 2026-10-10 00:59 UTCGHSA enrichmentGHSA-9rqj-cvwq-v6qh · GitHub CVSS 4.3
  12. 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.6% · 44th percentile
  13. 2026-10-09 02:43 UTCEG score recompute
  14. 2026-10-09 02:43 UTCVendor advisory
  15. 2026-10-09 02:43 UTCGHSA enrichmentGHSA-9rqj-cvwq-v6qh · GitHub CVSS 4.3
  16. 2026-10-08 17:12 UTCEPSS rescoreEPSS 0.6% · 44th percentile
  17. 2026-10-08 00:55 UTCEG score recompute
  18. 2026-10-08 00:55 UTCVendor advisory
  19. 2026-10-08 00:55 UTCGHSA enrichmentGHSA-9rqj-cvwq-v6qh · GitHub CVSS 4.3
  20. 2026-10-07 23:47 UTCEPSS rescoreEPSS 0.6% · 44th percentile
  21. 2026-10-06 15:55 UTCEG score recompute
  22. 2026-10-06 15:55 UTCGHSA enrichmentGHSA-9rqj-cvwq-v6qh · GitHub CVSS 4.3
  23. 2026-10-06 15:17 UTCEPSS rescoreEPSS 0.6% · 44th percentile
  24. 2026-10-05 17:42 UTCEPSS rescoreEPSS 0.6% · 44th percentile
  25. 2026-10-05 17:39 UTCEG score recompute
Show 74 more
  1. 2026-10-05 17:39 UTCGHSA enrichmentGHSA-9rqj-cvwq-v6qh · GitHub CVSS 4.3
  2. 2026-10-04 23:22 UTCEPSS rescoreEPSS 0.6% · 44th percentile
  3. 2026-10-04 19:36 UTCGHSA enrichmentGHSA-9rqj-cvwq-v6qh · GitHub CVSS 4.3
  4. 2026-10-03 20:57 UTCEG score recompute
  5. 2026-10-03 20:57 UTCGHSA enrichmentGHSA-9rqj-cvwq-v6qh · GitHub CVSS 4.3
  6. 2026-10-03 14:25 UTCEPSS rescoreEPSS 0.6% · 44th percentile
  7. 2026-10-02 22:54 UTCEG score recompute
  8. 2026-10-02 22:54 UTCGHSA enrichmentGHSA-9rqj-cvwq-v6qh · GitHub CVSS 4.3
  9. 2026-10-02 00:37 UTCEG score recompute
  10. 2026-10-02 00:37 UTCGHSA enrichmentGHSA-9rqj-cvwq-v6qh · GitHub CVSS 4.3
  11. 2026-10-01 19:49 UTCEPSS rescoreEPSS 0.6% · 44th percentile
  12. 2026-10-01 02:11 UTCEG score recompute
  13. 2026-10-01 02:11 UTCGHSA enrichmentGHSA-9rqj-cvwq-v6qh · GitHub CVSS 4.3
  14. 2026-09-30 15:03 UTCEPSS rescoreEPSS 0.6% · 44th percentile
  15. 2026-09-30 03:52 UTCEG score recompute
  16. 2026-09-30 03:52 UTCGHSA enrichmentGHSA-9rqj-cvwq-v6qh · GitHub CVSS 4.3
  17. 2026-09-29 02:59 UTCEG score recompute
  18. 2026-09-29 02:59 UTCGHSA enrichmentGHSA-9rqj-cvwq-v6qh · GitHub CVSS 4.3
  19. 2026-09-28 13:51 UTCEPSS rescoreEPSS 0.4% · 27th percentile
  20. 2026-09-28 04:55 UTCEG score recompute
  21. 2026-09-28 04:55 UTCGHSA enrichmentGHSA-9rqj-cvwq-v6qh · GitHub CVSS 4.3
  22. 2026-09-27 13:48 UTCEPSS rescoreEPSS 0.4% · 27th percentile
  23. 2026-09-27 06:50 UTCEG score recompute
  24. 2026-09-27 06:50 UTCGHSA enrichmentGHSA-9rqj-cvwq-v6qh · GitHub CVSS 4.3
  25. 2026-09-26 15:58 UTCEPSS rescoreEPSS 0.4% · 27th percentile
  26. 2026-09-26 08:45 UTCEG score recompute
  27. 2026-09-26 08:45 UTCGHSA enrichmentGHSA-9rqj-cvwq-v6qh · GitHub CVSS 4.3
  28. 2026-09-26 00:26 UTCEPSS rescoreEPSS 0.4% · 27th percentile
  29. 2026-09-25 05:24 UTCEG score recompute
  30. 2026-09-25 05:24 UTCGHSA enrichmentGHSA-9rqj-cvwq-v6qh · GitHub CVSS 4.3
  31. 2026-09-24 07:21 UTCEG score recompute
  32. 2026-09-24 07:21 UTCGHSA enrichmentGHSA-9rqj-cvwq-v6qh · GitHub CVSS 4.3
  33. 2026-09-23 09:17 UTCEG score recompute
  34. 2026-09-23 09:17 UTCGHSA enrichmentGHSA-9rqj-cvwq-v6qh · GitHub CVSS 4.3
  35. 2026-09-22 11:13 UTCEG score recompute
  36. 2026-09-22 11:13 UTCGHSA enrichmentGHSA-9rqj-cvwq-v6qh · GitHub CVSS 4.3
  37. 2026-09-21 13:09 UTCEG score recompute
  38. 2026-09-21 13:09 UTCGHSA enrichmentGHSA-9rqj-cvwq-v6qh · GitHub CVSS 4.3
  39. 2026-09-20 20:15 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  40. 2026-09-20 15:05 UTCGHSA enrichmentGHSA-9rqj-cvwq-v6qh · GitHub CVSS 4.3
  41. 2026-09-19 17:01 UTCEG score recompute
  42. 2026-09-19 17:01 UTCGHSA enrichmentGHSA-9rqj-cvwq-v6qh · GitHub CVSS 4.3
  43. 2026-09-18 19:28 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  44. 2026-09-18 18:56 UTCGHSA enrichmentGHSA-9rqj-cvwq-v6qh · GitHub CVSS 4.3
  45. 2026-09-17 20:52 UTCEG score recompute
  46. 2026-09-17 20:52 UTCGHSA enrichmentGHSA-9rqj-cvwq-v6qh · GitHub CVSS 4.3
  47. 2026-09-17 19:30 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  48. 2026-09-16 18:58 UTCEG score recompute
  49. 2026-09-16 18:58 UTCGHSA enrichmentGHSA-9rqj-cvwq-v6qh · GitHub CVSS 4.3
  50. 2026-09-16 14:08 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  51. 2026-09-16 05:15 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  52. 2026-09-15 18:58 UTCEG score recompute
  53. 2026-09-15 18:57 UTCGHSA enrichmentGHSA-9rqj-cvwq-v6qh · GitHub CVSS 4.3
  54. 2026-09-15 03:11 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  55. 2026-09-14 20:53 UTCGHSA enrichmentGHSA-9rqj-cvwq-v6qh · GitHub CVSS 4.3
  56. 2026-09-13 22:49 UTCEG score recompute
  57. 2026-09-13 22:49 UTCGHSA enrichmentGHSA-9rqj-cvwq-v6qh · GitHub CVSS 4.3
  58. 2026-09-13 16:47 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  59. 2026-09-13 00:45 UTCEG score recompute
  60. 2026-09-13 00:45 UTCGHSA enrichmentGHSA-9rqj-cvwq-v6qh · GitHub CVSS 4.3
  61. 2026-09-12 15:01 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  62. 2026-09-12 02:41 UTCEG score recompute
  63. 2026-09-12 02:41 UTCGHSA enrichmentGHSA-9rqj-cvwq-v6qh · GitHub CVSS 4.3
  64. 2026-09-11 14:53 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  65. 2026-09-11 04:37 UTCEG score recompute
  66. 2026-09-11 04:37 UTCGHSA enrichmentGHSA-9rqj-cvwq-v6qh · GitHub CVSS 4.3
  67. 2026-09-10 09:34 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  68. 2026-09-10 06:33 UTCGHSA enrichmentGHSA-9rqj-cvwq-v6qh · GitHub CVSS 4.3
  69. 2026-09-09 08:29 UTCEG score recompute
  70. 2026-09-09 08:29 UTCGHSA enrichmentGHSA-9rqj-cvwq-v6qh · GitHub CVSS 4.3
  71. 2026-09-08 22:00 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  72. 2026-09-08 10:26 UTCEG score recompute
  73. 2026-09-08 10:25 UTCGHSA enrichmentGHSA-9rqj-cvwq-v6qh · GitHub CVSS 4.3
  74. 2026-09-07 16:01 UTCEPSS rescoreEPSS 0.3% · 21st percentile

Related CVEs(same product + same vendor + same CWE)

Frequently asked(5)

What is CVE-2026-33263?
CVE-2026-33263 is a medium-severity vulnerability; its CVE record was published on August 28, 2026. When mailmaxuserip_connections is set (default 10) and reached, submission-login can crash with epoll() panic caused by file descriptor handling issues. If running in high-security mode (default for community releases), only the new submission connection gets terminated. If running in…
When was the CVE record for CVE-2026-33263 published?
The CVE record for CVE-2026-33263 was published on August 28, 2026. That is the record's publication date; the vulnerability itself may have been made public earlier. EchelonGraph's copy of the record carries a last-modified date of September 3, 2026; the record at its source may have been updated since.
Is CVE-2026-33263 actively exploited?
CVE-2026-33263 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.6% probability of exploitation in the next 30 days (44th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-33263?
CVE-2026-33263 has a CVSS base score of 4.3 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-33263?
A fix for CVE-2026-33263 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-33263 are linked in the Vendor Advisories panel on this page.

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