CVE-2026-61911

MEDIUMPre-NVD 4.34.3—
EchelonGraph scoreHIGH confidence

Score 4.3 from GitHub Security Advisory published 2026-09-09. 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.

An issue was discovered in Cyrus IMAP before 3.12.4. There is a Sieve mailbox existence oracle. An authenticated user could install a Sieve script that probed whether another user's private mailbox existed, or read the value of shared mailbox annotations, by observing which fileinto branch fired during LMTP delivery.

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
12%
KEV
Not listed

Published

September 9, 2026

Last Modified

September 16, 2026

Advisory Details (4)

Auto-updated Sep 9, 2026
No patch confirmed yet.
generic

Cyrus IMAP 3.8.8 Release Notes — Cyrus IMAP 3.12.4 documentation

https://www.cyrusimap.org/3.12/imap/download/release-notes/3.8/x/3.8.8.html
generic

Cyrus IMAP 3.12.4 Release Notes — Cyrus IMAP 3.12.4 documentation

https://www.cyrusimap.org/3.12/imap/download/release-notes/3.12/x/3.12.4.html
generic

Cyrus IMAP 3.10.4 Release Notes — Cyrus IMAP 3.12.4 documentation

https://www.cyrusimap.org/3.12/imap/download/release-notes/3.10/x/3.10.4.html
generic

What is Cyrus IMAP? — Cyrus IMAP 3.12.4 documentation

https://cyrusimap.org

Vendor Advisories for CVE-2026-61911(1)

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

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 17× in last 7d / 29× 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. 2026-09-19 16:27 UTCEG score recompute
  2. 2026-09-19 16:27 UTCGHSA enrichment
  3. 2026-09-18 19:28 UTCEPSS rescore
  4. 2026-09-18 16:13 UTCEG score recompute
  5. 2026-09-18 16:13 UTCGHSA enrichment
  6. 2026-09-17 15:58 UTCGHSA enrichment
  7. 2026-09-16 15:43 UTCEG score recompute
  8. 2026-09-16 15:43 UTCGHSA enrichment
  9. 2026-09-16 14:08 UTCEPSS rescore
  10. 2026-09-16 05:15 UTCEPSS rescore
  11. 2026-09-15 20:50 UTCEG score recompute
  12. 2026-09-15 20:50 UTCGHSA enrichment
  13. 2026-09-14 20:17 UTCGHSA enrichment
  14. 2026-09-13 20:03 UTCEG score recompute
  15. 2026-09-13 20:03 UTCGHSA enrichment
  16. 2026-09-12 19:49 UTCEG score recompute
  17. 2026-09-12 19:49 UTCGHSA enrichment
  18. 2026-09-11 19:35 UTCEG score recompute
  19. 2026-09-11 19:35 UTCGHSA enrichment
  20. 2026-09-11 14:53 UTCEPSS rescore
  21. 2026-09-11 09:37 UTCEPSS rescore
  22. 2026-09-10 19:20 UTCEG score recompute
  23. 2026-09-10 19:20 UTCGHSA enrichment
  24. 2026-09-10 19:10 UTCEG score recompute
  25. 2026-09-10 19:10 UTCGHSA enrichment
Show 4 more
  1. 2026-09-09 20:30 UTCEG score recompute▲ 4.30
  2. 2026-09-09 20:29 UTCNVD updateCVSS v3 → 4.3 · severity → MEDIUM
  3. 2026-09-09 20:00 UTCEG score recompute
  4. 2026-09-09 19:59 UTCMITRE cvelistV5first tracked

Frequently asked(5)

What is CVE-2026-61911?
CVE-2026-61911 is a medium vulnerability published on September 9, 2026. An issue was discovered in Cyrus IMAP before 3.12.4. There is a Sieve mailbox existence oracle. An authenticated user could install a Sieve script that probed whether another user's private mailbox existed, or read the value of shared mailbox annotations, by observing which fileinto branch fired…
When was CVE-2026-61911 disclosed?
CVE-2026-61911 was first published in the National Vulnerability Database on September 9, 2026, with the most recent update on September 16, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-61911 actively exploited?
CVE-2026-61911 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 87.5% of all scored CVEs.
What is the CVSS score of CVE-2026-61911?
CVE-2026-61911 has a CVSS v3 base score of 4.3 (NVD).
How do I remediate CVE-2026-61911?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-61911, 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

Explore the affected products and dependency analysis for CVE-2026-61911

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