CVE Intelligence
Medium Memory corruption

CVE-2026-94184 — Fetchmail: fetchmail: stack-based buffer overflow in ntlm authentication (fetchmail-sa-2026-01)

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.

Published Sep 21, 2026 · Updated Oct 15, 2026 · Sources: NIST National Vulnerability Database, CVE Program (cve.org) e CISA ADP · CNA: redhat

Who exploits it and how urgent it is

A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.

No exploitation signal in the sources consulted so far.
How the score was calculated
  • EPSS 0.8% (30-day exploitation probability)+8
  • Technical severity (medium)+3

The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).

Triage

Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.

Exploitation
Not confirmed
Not in CISA KEV — an absence of record, not proof it is unexploited.
EPSS FIRST
0.82%
ahead of 56% of scored CVEs · Oct 15, 2026
Affects
Red Hat
Red Hat Enterprise Linux 10 and 4 more
CVSS base
5.3
Medium · 4 source(s)
Prioritization reference: 8.1 provisional

CISA SSVC assessment CISA

Three decision points CISA publishes for the CVEs it assesses (SSVC 2.0.3). A stakeholder decision, not a severity score.

Exploitation
None
none · proof-of-concept · active
Automatable
No
can an attacker script the kill-chain steps
Technical impact
Total
partial · total control of the vulnerable component

Remediation

Fixes and mitigations documented by the sources — linked to the original advisory.

No fix documented by the sources we poll. That does not mean none exists: check the vendor advisory.

First 24 hours

Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.

  1. Identify exposed assets running the affected vendor/product/version combinations (Red Hat Red Hat Enterprise Linux 10, Red Hat Red Hat Enterprise Linux 6, Red Hat Red Hat Enterprise Linux 7…).
  2. The attack is network-based and needs no privileges: restrict exposure (ACLs, VPN, WAF) until patched.
  3. No fix documented in the sources: reduce exposure and monitor the vendor advisory.
  4. Search available logs for exploit probes matching the vulnerability class (memory corruption), errors and authentication anomalies.

Affected scope

Vendor, product and versions as the sources word them.

VendorProductVersionsStatusSource
Red Hat Red Hat Enterprise Linux 10 versions not specified by the source Vulnerable CVE Program (cve.org) e CISA ADP
Red Hat Red Hat Enterprise Linux 6 versions not specified by the source Vulnerable CVE Program (cve.org) e CISA ADP
Red Hat Red Hat Enterprise Linux 7 versions not specified by the source Vulnerable CVE Program (cve.org) e CISA ADP
Red Hat Red Hat Enterprise Linux 8 versions not specified by the source Vulnerable CVE Program (cve.org) e CISA ADP
Red Hat Red Hat Enterprise Linux 9 versions not specified by the source Vulnerable CVE Program (cve.org) e CISA ADP

Attack characteristics

The CVSS vector, decoded. It describes the attack, not your exposure to it.

Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
Low

Every base score collected

Sources score independently and may disagree; each row says who scored it and under which version.

ScoreVersionSeverityExpl.ImpactScored by
8.1 CVSS 3.1 High 2.2 5.9 134c704f-9b21-4f2e-91b3-4a467353bcc0 via NIST National Vulnerability Database
8.1 CVSS 3.1 High — — CISA-ADP via CVE Program (cve.org) e CISA ADP
5.3 CVSS 3.1 Medium 3.9 1.4 secalert@redhat.com via NIST National Vulnerability Database
5.3 CVSS 3.1 Medium — — redhat via CVE Program (cve.org) e CISA ADP
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L (score shown at the top: secalert@redhat.com)
Scoring entities (NIST, CNA, ADP) score independently; each score is shown with its origin. For prioritization we use 8.1 (CISA ADP via NIST National Vulnerability Database) as a conservative provisional reference — not a definitive official score.

Weakness MITRE

Weakness class according to MITRE’s CWE catalog.

CWE-121 · Stack-based Buffer Overflow

Other CVEs with this weakness →

Detection

Read off the CVSS vector and the weakness class. Starting points, not tested rules.

  • Prioritize edge telemetry for the network-reachable component (proxy, WAF, IDS/IPS).
  • Correlate service crashes/restarts with inbound traffic; repeated crashes may indicate attempts.
web/proxy/WAF logsnetwork IDS/IPSendpoint telemetry (EDR)crash dumps

Timeline

What happened to this CVE, newest first.

  • 2026
  • Affected products added · red hat/red hat enterprise linux 10, red hat/red hat enterprise linux 6, red hat/red hat enterprise linux 7, red hat/red
    Oct 15, 2026 · CVE Program (cve.org) e CISA ADP
  • SSVC assessment updated
    Oct 15, 2026 · CVE Program (cve.org) e CISA ADP
  • Record published
    Oct 15, 2026
  • CVSS changed · 5.3
    Oct 15, 2026 · NIST National Vulnerability Database
  • Source status changed · → Awaiting Analysis
    Oct 15, 2026 · NIST National Vulnerability Database
  • Record created in this database
    Oct 15, 2026 · NIST National Vulnerability Database
  • CVE published
    Sep 21, 2026 · redhat

Source activity

Repeated readings are counted rather than listed.

  • 1× Official description updated · Oct 15, 2026 – Oct 15, 2026

References

7 on the record

Elsewhere on this site

Red Hat
every CVE for this vendor
Memory corruption
same class
CWE-121
other pages naming this weakness

Related CVEs (same products)

  • CVE-2026-111581 Libblockdev: libblockdev: argument injection in ntfs/vfat label-setting helpers via udisks2 setlabel() d-bus method 1h
  • CVE-2026-111555 Luksmeta: missing slot-range validation permits out-of-gap device i/o 4h
  • CVE-2026-105958 Spice-server: spice: heap oob read/write via unchecked migration data offsets 4h
  • CVE-2026-105959 Spice-server: spice: heap buffer overflow via glz dictionary max_encoders integer truncation 5h
  • CVE-2026-104715 Cifs-utils: mount.cifs credential-file option injection allows local privilege boundary bypass 10h
  • CVE-2026-110924 Openssh: openssh: gssapi delegated credentials can be stored after a failed authentication 1d

Not in any source we poll

Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.

  • No fixed version, patch or mitigation documented.
  • No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
  • No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
  • No exploit packet captures, log samples, or incident case IDs supplied.

Answered from this record

Text assembled only from the fields above — no additional claims.

What should defenders know first?

CVE-2026-94184 is "Fetchmail: fetchmail: stack-based buffer overflow in ntlm authentication (fetchmail-sa-2026-01)", rated Medium. It affects Red Hat Enterprise Linux 10 (Red Hat); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 5.3 describes technical severity. EPSS 0.82% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.

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