CVE-2026-94184

Fetchmail: fetchmail: stack-based buffer overflow in ntlm authentication (fetchmail-sa-2026-01)

Products / packages Red Hat Enterprise Linux 10 · Red Hat Enterprise Linux 8 · Red Hat Enterprise Linux 9 · 2 more

Published 21/09/2026, 14:17:16 UTC

Severity and exploitation

Not in CISA KEV

KEV coverage does not rule out exploitation.

KEV checked 14/11/2026, 21:25:33 UTC

redhat · CVSS:3.1 · 5.3

Assessment vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

CISA-ADP · CVSS:3.1 · 8.1

Assessment vector

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

The headline uses the highest imported catalog score. Assessments can differ by source and CVSS version.

Severity

high8.1

CVSS measures technical severity, not the likelihood of an attack.

Known exploitation

Not listed in the checked CISA KEV catalog

Absence from CISA KEV does not rule out attacks.

Public exploit

Not established by this record

Missing evidence does not mean no public exploit exists.

Remediation

Source guidance available

Review the recorded instructions. Guidance may be a workaround rather than a fixed version.

What this means

Fetchmail has a stack-based buffer overflow flaw when built with NTLM support, potentially causing authentication failure or process termination. A malicious mail server can send a crafted Type 2 challenge. The impact may depend on stack-frame layout.

Summarized by @cf/meta/llama-3.3-70b-instruct-fp8-fast. Verify details against the original sources.

Attack conditions

No attack-condition excerpt has been identified here. Review the full source description and references for authentication, network access, and configuration requirements.

Review supporting sources →

Affected versions

Check the exact model, release, and any platform requirements against your installation.

Red Hat · redhat

Red Hat Enterprise Linux 10

1 range

redhat version evidence

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Compare with this publisher’s ranges. This does not inspect your installation.

unaffected

0:6.4.38-3.el10_2.1 → before *

rpm versions

Other versions: affected

Product identifiers (CPE)

cpe:/o:redhat:enterprise_linux:10.2

Red Hat · redhat

Red Hat Enterprise Linux 10

1 range

redhat version evidence

Check a product version

Compare with this publisher’s ranges. This does not inspect your installation.

unaffected

0:6.4.38-3.el10_3.1 → before *

rpm versions

Other versions: affected

Product identifiers (CPE)

cpe:/o:redhat:enterprise_linux:10.3

Red Hat · redhat

Red Hat Enterprise Linux 8

1 range

redhat version evidence

Check a product version

Compare with this publisher’s ranges. This does not inspect your installation.

unaffected

0:6.4.24-1.el8_10.1 → before *

rpm versions

Other versions: affected

Product identifiers (CPE)

cpe:/a:redhat:enterprise_linux:8::appstream

Red Hat · redhat

Red Hat Enterprise Linux 9

1 range

redhat version evidence

Check a product version

Compare with this publisher’s ranges. This does not inspect your installation.

unaffected

0:6.4.24-1.el9_8.1 → before *

rpm versions

Other versions: affected

Product identifiers (CPE)

cpe:/a:redhat:enterprise_linux:9::appstream

Red Hat · redhat

Red Hat Enterprise Linux 9

1 range

redhat version evidence

Check a product version

Compare with this publisher’s ranges. This does not inspect your installation.

unaffected

0:6.4.24-1.el9_9.1 → before *

rpm versions

Other versions: affected

Product identifiers (CPE)

cpe:/a:redhat:enterprise_linux:9::appstream

Red Hat · redhat

Red Hat Enterprise Linux 6

0 ranges

redhat version evidence

Check a product version

Compare with this publisher’s ranges. This does not inspect your installation.

Other versions: affected

Product identifiers (CPE)

cpe:/o:redhat:rhel_els:6

Red Hat · redhat

Red Hat Enterprise Linux 7

0 ranges

redhat version evidence

Check a product version

Compare with this publisher’s ranges. This does not inspect your installation.

Other versions: affected

Product identifiers (CPE)

cpe:/o:redhat:rhel_els:7

Automatic dependency matching is unavailable for this record. Use the product evidence and publisher’s instructions to check your installation.

What to do

Compare your installed product and version with the affected versions above. A matching product name alone does not confirm exposure.

Rebuild fetchmail without --enable-NTLM (omit NTLM at configure time). Confirm with fetchmail -V that the build does not list +NTLM.

redhat guidance ↗

cve.new guidance unless attributed to a publisher. This page does not inspect your installation.

Public exploit evidence

No public exploit reference is identified in the imported evidence. This is not a claim that no exploit exists.

Original source description

Read the full publisher description

A stack-based buffer overflow flaw was found in fetchmail when built with NTLM support. A malicious or compromised mail server advertising NTLM authentication can send a crafted Type 2 challenge that causes fetchmail to write past a fixed stack buffer while building the NTLM authenticate response. This may lead to remote code execution depending on stack-frame layout, or to authentication failure or process termination under memory hardening.

References

12 sources

access.redhat.com/errata/RHSA-2026:85959

Vendor advisoryredhat

access.redhat.com/errata/RHSA-2026:86981

Vendor advisoryredhat

access.redhat.com/errata/RHSA-2026:86982

Vendor advisoryredhat

access.redhat.com/errata/RHSA-2026:98480

Vendor advisoryredhat

access.redhat.com/errata/RHSA-2026:98583

Vendor advisoryredhat

access.redhat.com/security/cve/CVE-2026-94184

Security advisoryredhat

View 6 more references

bugzilla.redhat.com/show_bug.cgi

Source referenceredhat

bugzilla.redhat.com/show_bug.cgi

Source referenceredhat

gitlab.com/fetchmail/fetchmail/-/commit/cb5be5c38471eec19e519ace0bc569176317ea92

Patchredhat

www.fetchmail.info/fetchmail-SA-2026-01.txt

Source referenceredhat

www.openwall.com/lists/oss-security/2026/06/27/8

Security advisoryredhat

www.openwall.com/lists/oss-security/2026/09/23/1

Security advisoryCVE

Inside the record

Evidence available

Package identity · not supplied

Version evidence

Remediation guidance

Weakness classification

Additional publishers

Describes the evidence in this view, not whether the product is safe.

Original records

CVE-2026-94184

View the latest unmodified CVE JSON from the official source. It may be newer than this imported page.

cve.new JSON →

Underlying weaknesses

The source’s classification of what caused the vulnerability.

CWE-121 ↗

Stack-based Buffer Overflow

redhat

Contributing organizations · 3

redhat

Assigning organization

2026-11-11

CISA-ADP

Additional data publisher

2026-09-24

CVE

Additional data publisher

2026-09-23

Timeline

All times UTC

21 Sept 2026, 14:17
Advisory published
Publication date supplied by the source.
11 Nov 2026, 12:59
Source updated
Latest modification date supplied by the source.
11 Nov 2026, 13:20
Last imported by cve.new
Latest catalog import, not the date we first saw this advisory.

What changed

Follow changes

CVE · CVE-2026-941842026-11-11

Observed 2026-11-11T13:20:30.178Z · upstream updated 2026-11-11T12:59:08.061Z

Product or version evidence changed

before

[
  {
    "vendor": "Red Hat",
    "name": "Red Hat Enterprise Linux 10",
    "platforms": [],
    "versions": [
      {
        "version": "0:6.4.38-3.el10_2.1",
        "status": "unaffected",
        "lessThan": "*",
        "versionType": "rpm"
      }
    ],
    "defaultStatus": "affected",
    "cpes": [
      "cpe:/o:redhat:enterprise_linux:10.2"
    ],
    "source": "redhat",
    "url": "https://www.cve.org/CVERecord?id=CVE-2026-94184"
  },
  {
    "vendor": "Red Hat",
    "name": "Red Hat Enterprise Linux 8",
    "platforms": [],
    "versions": [
      {
        "version": "0:6.4.24-1.el8_10.1",
        "status": "unaffected",
        "lessThan": "*",
        "versionType": "rpm"
      }
    ],
    "defaultStatus": "affected",
    "cpes": [
      "cpe:/a:redhat:enterprise_linux:8::appstream"
    ],
    "source": "redhat",
    "url": "https://www.cve.org/CVERecord?id=CVE-2026-94184"
  },
  {
    "vendor": "Red Hat",
    "name": "Red Hat Enterprise Linux 9",
    "platforms": [],
    "versions": [
      {
        "version": "0:6.4.24-1.el9_8.1",
        "status": "unaffected",
        "lessThan": "*",
        "versionType": "rpm"
      }
    ],
    "defaultStatus": "affected",
    "cpes": [
      "cpe:/a:redhat:enterprise_linux:9::appstream"
    ],
    "source": "redhat",
    "url": "https://www.cve.org/CVERecord?id=CVE-2026-94184"
  },
  {
    "vendor": "Red Hat",
    "name": "Red Hat Enterprise Linux 6",
    "platforms": [],
    "versions": [],
    "defaultStatus": "affected",
    "cpes": [
      "cpe:/o:redhat:rhel_els:6"
    ],
    "source": "redhat",
    "url": "https://www.cve.org/CVERecord?id=CVE-2026-94184"
  },
  {
    "vendor": "Red Hat",
    "name": "Red Hat Enterprise Linux 7",
    "platforms": [],
    "versions": [],
    "defaultStatus": "affected",
    "cpes": [
      "cpe:/o:redhat:rhel_els:7"
    ],
    "source": "redhat",
    "url": "https://www.cve.org/CVERecord?id=CVE-2026-94184"
  }
]

after

[
  {
    "vendor": "Red Hat",
    "name": "Red Hat Enterprise Linux 10",
    "platforms": [],
    "versions": [
      {
        "version": "0:6.4.38-3.el10_2.1",
        "status": "unaffected",
        "lessThan": "*",
        "versionType": "rpm"
      }
    ],
    "defaultStatus": "affected",
    "cpes": [
      "cpe:/o:redhat:enterprise_linux:10.2"
    ],
    "source": "redhat",
    "url": "https://www.cve.org/CVERecord?id=CVE-2026-94184"
  },
  {
    "vendor": "Red Hat",
    "name": "Red Hat Enterprise Linux 10",
    "platforms": [],
    "versions": [
      {
        "version": "0:6.4.38-3.el10_3.1",
        "status": "unaffected",
        "lessThan": "*",
        "versionType": "rpm"
      }
    ],
    "defaultStatus": "affected",
    "cpes": [
      "cpe:/o:redhat:enterprise_linux:10.3"
    ],
    "source": "redhat",
    "url": "https://www.cve.org/CVERecord?id=CVE-2026-94184"
  },
  {
    "vendor": "Red Hat",
    "name": "Red Hat Enterprise Linux 8",
    "platforms": [],
    "versions": [
      {
        "version": "0:6.4.24-1.el8_10.1",
        "status": "unaffected",
        "lessThan": "*",
        "versionType": "rpm"
      }
    ],
    "defaultStatus": "affected",
    "cpes": [
      "cpe:/a:redhat:enterprise_linux:8::appstream"
    ],
    "source": "redhat",
    "url": "https://www.cve.org/CVERecord?id=CVE-2026-94184"
  },
  {
    "vendor": "Red Hat",
    "name": "Red Hat Enterprise Linux 9",
    "platforms": [],
    "versions": [
      {
        "version": "0:6.4.24-1.el9_8.1",
        "status": "unaffected",
        "lessThan": "*",
        "versionType": "rpm"
      }
    ],
    "defaultStatus": "affected",
    "cpes": [
      "cpe:/a:redhat:enterprise_linux:9::appstream"
    ],
    "source": "redhat",
    "url": "https://www.cve.org/CVERecord?id=CVE-2026-94184"
  },
  {
    "vendor": "Red Hat",
    "name": "Red Hat Enterprise Linux 9",
    "platforms": [],
    "versions": [
      {
        "version": "0:6.4.24-1.el9_9.1",
        "status": "unaffected",
        "lessThan": "*",
        "versionType": "rpm"
      }
    ],
    "defaultStatus": "affected",
    "cpes": [
      "cpe:/a:redhat:enterprise_linux:9::appstream"
    ],
    "source": "redhat",
    "url": "https://www.cve.org/CVERecord?id=CVE-2026-94184"
  },
  {
    "vendor": "Red Hat",
    "name": "Red Hat Enterprise Linux 6",
    "platforms": [],
    "versions": [],
    "defaultStatus": "affected",
    "cpes": [
      "cpe:/o:redhat:rhel_els:6"
    ],
    "source": "redhat",
    "url": "https://www.cve.org/CVERecord?id=CVE-2026-94184"
  },
  {
    "vendor": "Red Hat",
    "name": "Red Hat Enterprise Linux 7",
    "platforms": [],
    "versions": [],
    "defaultStatus": "affected",
    "cpes": [
      "cpe:/o:redhat:rhel_els:7"
    ],
    "source": "redhat",
    "url": "https://www.cve.org/CVERecord?id=CVE-2026-94184"
  }
]

References changed

before

[
  "https://access.redhat.com/errata/RHSA-2026:85959",
  "https://access.redhat.com/errata/RHSA-2026:86981",
  "https://access.redhat.com/errata/RHSA-2026:86982",
  "https://access.redhat.com/security/cve/CVE-2026-94184",
  "https://bugzilla.redhat.com/show_bug.cgi?id=2531984",
  "https://bugzilla.redhat.com/show_bug.cgi?id=2537395",
  "https://gitlab.com/fetchmail/fetchmail/-/commit/cb5be5c38471eec19e519ace0bc569176317ea92",
  "https://www.fetchmail.info/fetchmail-SA-2026-01.txt",
  "https://www.openwall.com/lists/oss-security/2026/06/27/8",
  "http://www.openwall.com/lists/oss-security/2026/09/23/1"
]

after

[
  "https://access.redhat.com/errata/RHSA-2026:85959",
  "https://access.redhat.com/errata/RHSA-2026:86981",
  "https://access.redhat.com/errata/RHSA-2026:86982",
  "https://access.redhat.com/errata/RHSA-2026:98480",
  "https://access.redhat.com/errata/RHSA-2026:98583",
  "https://access.redhat.com/security/cve/CVE-2026-94184",
  "https://bugzilla.redhat.com/show_bug.cgi?id=2531984",
  "https://bugzilla.redhat.com/show_bug.cgi?id=2537395",
  "https://gitlab.com/fetchmail/fetchmail/-/commit/cb5be5c38471eec19e519ace0bc569176317ea92",
  "https://www.fetchmail.info/fetchmail-SA-2026-01.txt",
  "https://www.openwall.com/lists/oss-security/2026/06/27/8",
  "http://www.openwall.com/lists/oss-security/2026/09/23/1"
]

Large field values are marked as truncated previews. Original source snapshots remain retained.

Showing up to 50 most recent observed changes.

Reading the signals

Severity · CVSS: Technical impact and attack conditions. The headline is the highest imported catalog score; sources may disagree.
Observed exploitation · KEV: An absent or unavailable KEV listing does not establish that exploitation has not occurred.
Predicted exploitation · EPSS: 1.20% estimated probability in the next 30 days. 2026-11-05 · FIRST EPSS.

CISA-ADP · SSVC

CISA Coordinator · 2026-09-22

Exploitation: none
Automatable: no
Technical Impact: total

SSVC describes the publisher’s decision context. Your organization’s exposure and priorities may differ.

Record identifiers

Aliases: None recorded

Source evidence

Request a correction or dispute

Start with the assigning organization for this record. Include the CVE ID, the disputed information, and supporting evidence. A dispute does not itself reject a record.

Find the responsible CNA →Official dispute and escalation process ↗

CVE CVE-2026-94184

Enrichment coverage

NVDAvailable

Checked 06/11/2026, 03:25:35 UTC

GHSAAvailable

Checked 06/11/2026, 03:25:36 UTC

EUVDAvailable

Checked 06/11/2026, 03:25:36 UTC

EPSSAvailable

Checked 06/11/2026, 03:25:35 UTC

Additional source evidence

NVD · CVE-2026-94184

CVSS 5.3 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

Checked 06/11/2026, 03:25:35 UTC

NVD · CVE-2026-94184

CVSS 8.1 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

Checked 06/11/2026, 03:25:35 UTC

FIRST EPSS · CVE-2026-94184

EPSS 1.20% probability of exploitation in the next 30 days. Percentile: 68.18% · 2026-11-05

Checked 06/11/2026, 03:25:35 UTC

GitHub Advisory Database · GHSA-5pfw-5pv2-2pc6

CVSS 8.1 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

Checked 06/11/2026, 03:25:36 UTC

ENISA EUVD · EUVD-2026-83923

CVSS 8.1 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

Checked 06/11/2026, 03:25:36 UTC

Sponsored by MoxsoBuild security habits with adaptive training and phishing simulations.View as JSON

Fetchmail: fetchmail: stack-based buffer overflow in ntlm authentication (fetchmail-sa-2026-01)

Severity and exploitation

What this means

Attack conditions

Affected versions

Red Hat Enterprise Linux 10

affected

unaffected

unknown

Red Hat Enterprise Linux 10

affected

unaffected

unknown

Red Hat Enterprise Linux 8

affected

unaffected

unknown

Red Hat Enterprise Linux 9

affected

unaffected

unknown

Red Hat Enterprise Linux 9

affected

unaffected

unknown

Red Hat Enterprise Linux 6

affected

unaffected

unknown

Red Hat Enterprise Linux 7

affected

unaffected

unknown

What to do

Public exploit evidence

Original source description

References

Inside the record

Evidence available

Original records

Underlying weaknesses

Timeline

Advisory published

Source updated

Last imported by cve.new

What changed