CVE-2026-33263

MEDIUMPre-NVD 4.34.3—
EchelonGraph scoreHIGH confidence

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, ghsa, secondary
Trending — 3 sources updated this week
4.3EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 4.3Exploit: None knownExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

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
4.3(high)
EG Risk
19(Track)
EG Risk 19/100SSVC: 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
Severity43% × 45%
Exploitation0% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
22%
KEV
Not listed

Published

August 28, 2026

Last Modified

September 3, 2026

Advisory Details (1)

Auto-updated Aug 28, 2026
No patch confirmed yet.
generic
https://documentation.open-xchange.com/dovecot/security/advisories/csaf/2026/oxdc-adv-2026-0003.json

Vendor Advisories for CVE-2026-33263(1)

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

Affected Packages

(5 across 5 ecosystems)
Alpine:v3.23(1)
PackageVulnerable rangeFixed inDependents
dovecot—2.4.5-r0—
Alpine:v3.24(1)
PackageVulnerable rangeFixed inDependents
dovecot—2.4.5-r0—
Debian:12(1)
PackageVulnerable rangeFixed inDependents
dovecot1:2.3.19.1+dfsg1-2.1 ... 1:2.4.5+dfsg1-2 (42 versions)——
Debian:13(1)
PackageVulnerable rangeFixed inDependents
dovecot1:2.4.1+dfsg1-6 ... 1:2.4.5+dfsg1-2 (20 versions)——
Debian:14(1)
PackageVulnerable rangeFixed inDependents
dovecot1:2.4.1+dfsg1-6 ... 1:2.4.5+dfsg1-2 (14 versions)——

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 20× in last 7d / 68× 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.

  1. 2026-09-18 19:28 UTCEPSS rescore
  2. 2026-09-18 19:28 UTCEPSS rescore
  3. 2026-09-18 18:56 UTCGHSA enrichment
  4. 2026-09-17 20:52 UTCEG score recompute
  5. 2026-09-17 20:52 UTCGHSA enrichment
  6. 2026-09-17 19:30 UTCEPSS rescore
  7. 2026-09-16 18:58 UTCEG score recompute
  8. 2026-09-16 18:58 UTCGHSA enrichment
  9. 2026-09-16 14:08 UTCEPSS rescore
  10. 2026-09-16 05:15 UTCEPSS rescore
  11. 2026-09-15 18:58 UTCEG score recompute
  12. 2026-09-15 18:57 UTCGHSA enrichment
  13. 2026-09-15 03:11 UTCEPSS rescore
  14. 2026-09-14 20:53 UTCGHSA enrichment
  15. 2026-09-13 22:49 UTCEG score recompute
  16. 2026-09-13 22:49 UTCGHSA enrichment
  17. 2026-09-13 16:47 UTCEPSS rescore
  18. 2026-09-13 00:45 UTCEG score recompute
  19. 2026-09-13 00:45 UTCGHSA enrichment
  20. 2026-09-12 15:01 UTCEPSS rescore
  21. 2026-09-12 02:41 UTCEG score recompute
  22. 2026-09-12 02:41 UTCGHSA enrichment
  23. 2026-09-11 14:53 UTCEPSS rescore
  24. 2026-09-11 04:37 UTCEG score recompute
  25. 2026-09-11 04:37 UTCGHSA enrichment
Show 43 more
  1. 2026-09-10 09:34 UTCEPSS rescore
  2. 2026-09-10 06:33 UTCGHSA enrichment
  3. 2026-09-09 08:29 UTCEG score recompute
  4. 2026-09-09 08:29 UTCGHSA enrichment
  5. 2026-09-08 22:00 UTCEPSS rescore
  6. 2026-09-08 10:26 UTCEG score recompute
  7. 2026-09-08 10:25 UTCGHSA enrichment
  8. 2026-09-07 16:01 UTCEPSS rescore
  9. 2026-09-07 10:53 UTCEG score recompute
  10. 2026-09-07 10:53 UTCGHSA enrichment
  11. 2026-09-06 13:47 UTCEPSS rescore
  12. 2026-09-06 13:47 UTCEPSS rescore
  13. 2026-09-06 12:41 UTCEG score recompute
  14. 2026-09-06 12:41 UTCGHSA enrichment
  15. 2026-09-05 14:37 UTCGHSA enrichment
  16. 2026-09-04 16:33 UTCEG score recompute
  17. 2026-09-04 16:33 UTCGHSA enrichment
  18. 2026-09-04 05:06 UTCEPSS rescore
  19. 2026-09-03 18:22 UTCGHSA enrichment
  20. 2026-09-03 08:54 UTCEG score recompute
  21. 2026-09-03 08:53 UTCGHSA enrichment
  22. 2026-09-02 14:11 UTCEPSS rescore
  23. 2026-09-02 10:50 UTCEG score recompute
  24. 2026-09-02 10:49 UTCGHSA enrichment
  25. 2026-09-01 13:53 UTCEPSS rescore
  26. 2026-09-01 12:40 UTCEG score recompute
  27. 2026-09-01 12:40 UTCGHSA enrichment
  28. 2026-09-01 04:39 UTCEPSS rescore
  29. 2026-09-01 04:39 UTCEPSS rescore
  30. 2026-08-31 14:34 UTCEG score recompute
  31. 2026-08-31 14:34 UTCGHSA enrichment
  32. 2026-08-30 19:17 UTCEPSS rescore
  33. 2026-08-30 16:30 UTCEG score recompute
  34. 2026-08-30 16:30 UTCGHSA enrichment
  35. 2026-08-30 01:22 UTCEPSS rescore
  36. 2026-08-29 18:26 UTCGHSA enrichment
  37. 2026-08-28 20:21 UTCEG score recompute
  38. 2026-08-28 20:21 UTCGHSA enrichment
  39. 2026-08-28 19:45 UTCEG score recompute
  40. 2026-08-28 19:45 UTCGHSA enrichment
  41. 2026-08-28 12:23 UTCEG score recompute
  42. 2026-08-28 11:25 UTCEG score recompute
  43. 2026-08-28 11:19 UTCMITRE cvelistV5first tracked

Frequently asked(5)

What is CVE-2026-33263?
CVE-2026-33263 is a medium vulnerability 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 CVE-2026-33263 disclosed?
CVE-2026-33263 was first published in the National Vulnerability Database on August 28, 2026, with the most recent update on September 3, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-33263 actively exploited?
CVE-2026-33263 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 78.2% of all scored CVEs.
What is the CVSS score of CVE-2026-33263?
CVE-2026-33263 has a CVSS v3 base score of 4.3 (NVD).
How do I remediate CVE-2026-33263?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-33263, 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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