CVE-2026-40013

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 — 3 sources updated 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: 0.9%CVSS: 4.3Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

An attacker that has valid credentials can submit a Sieve script containing an extreme numeric literal, which causes an out-of-bounds write when the ManageSieve service compiles the script. This causes memory corruption and an observed crash of the ManageSieve process, resulting in denial of service for script management. This might be able to be used for remote code execution. Disable the ManageSieve service if users do not need remote Sieve script management. 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.
Exploitation0.9% × 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
0.9%
EPSS %ILE
57th
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.

Vendor Advisories for CVE-2026-40013(1)

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

Affected Packages

(3 across 3 ecosystems)
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 17× in last 7d / 75× 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 124 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 25 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 0.9% · 57th percentile
  2. 2026-10-12 16:34 UTCEPSS rescoreEPSS 0.9% · 57th percentile
  3. 2026-10-12 16:09 UTCEG score recompute
  4. 2026-10-11 19:52 UTCEG score recompute
  5. 2026-10-11 17:05 UTCEG score recompute
  6. 2026-10-11 14:32 UTCEG score recompute
  7. 2026-10-11 13:48 UTCEPSS rescoreEPSS 0.9% · 57th percentile
  8. 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.9% · 57th percentile
  9. 2026-10-10 06:49 UTCEG score recompute
  10. 2026-10-10 06:49 UTCGHSA enrichmentGHSA-jh33-8ccj-9h78 · GitHub CVSS 4.3
  11. 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.9% · 57th percentile
  12. 2026-10-09 07:01 UTCEG score recompute
  13. 2026-10-09 07:01 UTCGHSA enrichmentGHSA-jh33-8ccj-9h78 · GitHub CVSS 4.3
  14. 2026-10-08 17:12 UTCEPSS rescoreEPSS 0.9% · 57th percentile
  15. 2026-10-08 06:59 UTCEG score recompute
  16. 2026-10-08 06:59 UTCGHSA enrichmentGHSA-jh33-8ccj-9h78 · GitHub CVSS 4.3
  17. 2026-10-07 23:48 UTCEPSS rescoreEPSS 0.9% · 57th percentile
  18. 2026-10-07 07:13 UTCEG score recompute
  19. 2026-10-07 07:13 UTCGHSA enrichmentGHSA-jh33-8ccj-9h78 · GitHub CVSS 4.3
  20. 2026-10-06 15:17 UTCEPSS rescoreEPSS 0.9% · 57th percentile
  21. 2026-10-06 07:28 UTCEG score recompute
  22. 2026-10-06 07:28 UTCGHSA enrichmentGHSA-jh33-8ccj-9h78 · GitHub CVSS 4.3
  23. 2026-10-05 17:43 UTCEPSS rescoreEPSS 0.9% · 57th percentile
  24. 2026-10-05 06:36 UTCEG score recompute
  25. 2026-10-05 06:36 UTCGHSA enrichmentGHSA-jh33-8ccj-9h78 · GitHub CVSS 4.3
Show 74 more
  1. 2026-10-04 23:22 UTCEPSS rescoreEPSS 0.9% · 57th percentile
  2. 2026-10-04 06:47 UTCEG score recompute
  3. 2026-10-04 06:47 UTCGHSA enrichmentGHSA-jh33-8ccj-9h78 · GitHub CVSS 4.3
  4. 2026-10-03 14:25 UTCEPSS rescoreEPSS 0.9% · 57th percentile
  5. 2026-10-03 07:02 UTCEG score recompute
  6. 2026-10-03 07:02 UTCGHSA enrichmentGHSA-jh33-8ccj-9h78 · GitHub CVSS 4.3
  7. 2026-10-02 07:17 UTCEG score recompute
  8. 2026-10-02 07:17 UTCGHSA enrichmentGHSA-jh33-8ccj-9h78 · GitHub CVSS 4.3
  9. 2026-10-01 19:50 UTCEPSS rescoreEPSS 0.9% · 57th percentile
  10. 2026-10-01 07:32 UTCEG score recompute
  11. 2026-10-01 07:32 UTCGHSA enrichmentGHSA-jh33-8ccj-9h78 · GitHub CVSS 4.3
  12. 2026-09-30 15:03 UTCEPSS rescoreEPSS 0.9% · 57th percentile
  13. 2026-09-30 07:47 UTCEG score recompute
  14. 2026-09-30 07:47 UTCGHSA enrichmentGHSA-jh33-8ccj-9h78 · GitHub CVSS 4.3
  15. 2026-09-29 07:59 UTCEG score recompute
  16. 2026-09-29 07:59 UTCGHSA enrichmentGHSA-jh33-8ccj-9h78 · GitHub CVSS 4.3
  17. 2026-09-28 08:14 UTCEG score recompute
  18. 2026-09-28 08:14 UTCGHSA enrichmentGHSA-jh33-8ccj-9h78 · GitHub CVSS 4.3
  19. 2026-09-27 13:48 UTCEPSS rescoreEPSS 0.6% · 44th percentile
  20. 2026-09-27 08:30 UTCEG score recompute
  21. 2026-09-27 08:30 UTCGHSA enrichmentGHSA-jh33-8ccj-9h78 · GitHub CVSS 4.3
  22. 2026-09-26 15:58 UTCEPSS rescoreEPSS 0.6% · 44th percentile
  23. 2026-09-26 08:44 UTCEG score recompute
  24. 2026-09-26 08:44 UTCGHSA enrichmentGHSA-jh33-8ccj-9h78 · GitHub CVSS 4.3
  25. 2026-09-26 00:26 UTCEPSS rescoreEPSS 0.6% · 44th percentile
  26. 2026-09-24 22:23 UTCEG score recompute
  27. 2026-09-24 22:23 UTCGHSA enrichmentGHSA-jh33-8ccj-9h78 · GitHub CVSS 4.3
  28. 2026-09-23 22:38 UTCEG score recompute
  29. 2026-09-23 22:38 UTCGHSA enrichmentGHSA-jh33-8ccj-9h78 · GitHub CVSS 4.3
  30. 2026-09-22 22:53 UTCEG score recompute
  31. 2026-09-22 22:53 UTCGHSA enrichmentGHSA-jh33-8ccj-9h78 · GitHub CVSS 4.3
  32. 2026-09-21 23:07 UTCEG score recompute
  33. 2026-09-21 23:07 UTCGHSA enrichmentGHSA-jh33-8ccj-9h78 · GitHub CVSS 4.3
  34. 2026-09-20 23:21 UTCGHSA enrichmentGHSA-jh33-8ccj-9h78 · GitHub CVSS 4.3
  35. 2026-09-19 23:33 UTCEG score recompute
  36. 2026-09-19 23:33 UTCGHSA enrichmentGHSA-jh33-8ccj-9h78 · GitHub CVSS 4.3
  37. 2026-09-18 23:48 UTCEG score recompute
  38. 2026-09-18 23:48 UTCGHSA enrichmentGHSA-jh33-8ccj-9h78 · GitHub CVSS 4.3
  39. 2026-09-18 19:28 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  40. 2026-09-18 00:01 UTCEG score recompute
  41. 2026-09-18 00:01 UTCGHSA enrichmentGHSA-jh33-8ccj-9h78 · GitHub CVSS 4.3
  42. 2026-09-17 19:30 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  43. 2026-09-16 23:15 UTCEG score recompute
  44. 2026-09-16 23:15 UTCGHSA enrichmentGHSA-jh33-8ccj-9h78 · GitHub CVSS 4.3
  45. 2026-09-16 14:08 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  46. 2026-09-16 05:15 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  47. 2026-09-15 23:29 UTCEG score recompute
  48. 2026-09-15 23:29 UTCGHSA enrichmentGHSA-jh33-8ccj-9h78 · GitHub CVSS 4.3
  49. 2026-09-15 03:11 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  50. 2026-09-14 23:37 UTCGHSA enrichmentGHSA-jh33-8ccj-9h78 · GitHub CVSS 4.3
  51. 2026-09-13 23:16 UTCEG score recompute
  52. 2026-09-13 23:16 UTCGHSA enrichmentGHSA-jh33-8ccj-9h78 · GitHub CVSS 4.3
  53. 2026-09-13 16:47 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  54. 2026-09-12 23:31 UTCEG score recompute
  55. 2026-09-12 23:31 UTCGHSA enrichmentGHSA-jh33-8ccj-9h78 · GitHub CVSS 4.3
  56. 2026-09-12 15:01 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  57. 2026-09-11 23:46 UTCEG score recompute
  58. 2026-09-11 23:46 UTCGHSA enrichmentGHSA-jh33-8ccj-9h78 · GitHub CVSS 4.3
  59. 2026-09-11 14:53 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  60. 2026-09-11 09:37 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  61. 2026-09-11 00:01 UTCEG score recompute
  62. 2026-09-11 00:00 UTCGHSA enrichmentGHSA-jh33-8ccj-9h78 · GitHub CVSS 4.3
  63. 2026-09-10 09:34 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  64. 2026-09-10 00:15 UTCGHSA enrichmentGHSA-jh33-8ccj-9h78 · GitHub CVSS 4.3
  65. 2026-09-09 00:30 UTCEG score recompute
  66. 2026-09-09 00:30 UTCGHSA enrichmentGHSA-jh33-8ccj-9h78 · GitHub CVSS 4.3
  67. 2026-09-08 22:00 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  68. 2026-09-07 17:29 UTCEG score recompute
  69. 2026-09-07 17:29 UTCGHSA enrichmentGHSA-jh33-8ccj-9h78 · GitHub CVSS 4.3
  70. 2026-09-07 16:01 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  71. 2026-09-06 17:44 UTCEG score recompute
  72. 2026-09-06 17:44 UTCGHSA enrichmentGHSA-jh33-8ccj-9h78 · GitHub CVSS 4.3
  73. 2026-09-06 13:47 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  74. 2026-09-05 17:58 UTCEG score recompute

Frequently asked(5)

What is CVE-2026-40013?
CVE-2026-40013 is a medium-severity vulnerability; its CVE record was published on August 28, 2026. An attacker that has valid credentials can submit a Sieve script containing an extreme numeric literal, which causes an out-of-bounds write when the ManageSieve service compiles the script. This causes memory corruption and an observed crash of the ManageSieve process, resulting in denial of…
When was the CVE record for CVE-2026-40013 published?
The CVE record for CVE-2026-40013 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-2026-40013 actively exploited?
CVE-2026-40013 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.9% probability of exploitation in the next 30 days (57th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-40013?
CVE-2026-40013 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-2026-40013?
A fix for CVE-2026-40013 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-40013 are linked in the Vendor Advisories panel on this page.

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