CVE Intelligence
CISA KEV High Memory corruption exploit reference

CVE-2017-11774 — Microsoft Office Outlook Security Feature Bypass Vulnerability

Microsoft Outlook 2010 SP2, Outlook 2013 SP1 and RT SP1, and Outlook 2016 allow an attacker to execute arbitrary commands, due to how Microsoft Office handles objects in memory, aka "Microsoft Outlook Security Feature Bypass Vulnerability."

Published Oct 13, 2017 · Updated Oct 13, 2026 · Sources: CISA Known Exploited Vulnerabilities, NIST National Vulnerability Database, CVE Program (cve.org) e CISA ADP, GitHub Security Advisories · CNA: microsoft

Who exploits it and how urgent it is

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

CISA KEV · Nov 3, 2021 ☠ APT33☠ OilRig
How the score was calculated
  • Confirmed exploitation (CISA KEV)+35
  • Exploited by 2 threat actor(s) (MITRE ATT&CK)+10
  • EPSS 59.6% (30-day exploitation probability)+15
  • Technical severity (high)+6

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
Confirmed
CISA KEV, listed Nov 3, 2021
EPSS FIRST
59.63%
ahead of 99% of scored CVEs · Oct 14, 2026
Affects
Microsoft
Outlook
CVSS base
7.8
High · 4 source(s)

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
Active
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.

CISA required action CISA

Apply updates per vendor instructions.

US federal deadline: May 3, 2022 — passed 1626 day(s) ago

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 (Microsoft Outlook).
  2. Treat as emergency remediation: the CVE is in CISA KEV (confirmed exploitation).
  3. Apply the fixed version or the patch documented under Remediation.
  4. Exploitation requires user interaction: tighten email/web filtering and warn affected users.
  5. EPSS ahead of 99% of scored CVEs: prioritize it in the patch queue.
  6. 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
Microsoft Outlook version 2010-sp2version 2013-sp1version 2016 Vulnerable NIST National Vulnerability Database
Microsoft Outlook version Microsoft Outlook 2010 SP2version Outlook 2013 SP1 and RT SP1version Outlook 2016 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
Local
Attack complexity
Low
Privileges required
None
User interaction
Required
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

Every base score collected

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

ScoreVersionSeverityExpl.ImpactScored by
7.8 CVSS 3.1 High 1.8 5.9 nvd@nist.gov via NIST National Vulnerability Database
7.8 CVSS 3.1 High 1.8 5.9 134c704f-9b21-4f2e-91b3-4a467353bcc0 via NIST National Vulnerability Database
7.8 CVSS 3.1 High — — CISA-ADP via CVE Program (cve.org) e CISA ADP
7.8 CVSS 3.0 High — — GitHub, Inc. via GitHub Security Advisories
6.8 CVSS 2.0 Medium 8.6 6.4 nvd@nist.gov via NIST National Vulnerability Database
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H (score shown at the top: nvd@nist.gov)

Weakness MITRE

Weakness class according to MITRE’s CWE catalog.

CWE-119 · Buffer Errors (Improper Restriction of Operations within Memory Bounds)

Other CVEs with this weakness →

CISA KEV details CISA

CISA lists a CVE once it has evidence of exploitation against real targets.

Listed
Nov 3, 2021
Federal deadline
May 3, 2022
passed 1626 day(s) ago
Ransomware use
Unknown

CISA records ransomware use only for campaigns it has confirmed, so “Unknown” means unrecorded, not ruled out. The deadline binds US federal agencies; for everyone else it is a reference date.

Threat actors exploiting this CVE MITRE ATT&CK

According to MITRE ATT&CK.

APT33 G0064OilRig G0049

EPSS over time FIRST

Oct 13, 2026 → Oct 14, 2026 · 2 reading(s) · max 59.63%

Detection

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

  • Local/physical vector: focus on endpoint telemetry (EDR) from affected hosts.
  • Correlate service crashes/restarts with inbound traffic; repeated crashes may indicate attempts.
  • Hunt retroactively in logs from before Nov 3, 2021 (KEV listing): exploitation may have started earlier.
endpoint telemetry (EDR)crash dumps

Timeline

What happened to this CVE, newest first.

  • 2026
  • Affected products added · microsoft corporation/microsoft outlook
    Oct 13, 2026 · CVE Program (cve.org) e CISA ADP
  • SSVC assessment updated
    Oct 13, 2026 · CVE Program (cve.org) e CISA ADP
  • Record published
    Oct 13, 2026
  • Fix documented
    Oct 13, 2026 · NIST National Vulnerability Database
  • Affected products added · microsoft/outlook
    Oct 13, 2026 · NIST National Vulnerability Database
  • CVSS changed · 7.8
    Oct 13, 2026 · NIST National Vulnerability Database
  • Source status changed · → Analyzed
    Oct 13, 2026 · NIST National Vulnerability Database
  • Added to CISA KEV (detected)
    Oct 13, 2026 · CISA Known Exploited Vulnerabilities
  • Record created in this database
    Oct 13, 2026 · CISA Known Exploited Vulnerabilities
  • 2021
  • Added to CISA KEV catalog
    Nov 2, 2021 · CISA
  • 2017
  • CVE published
    Oct 13, 2017 · microsoft

Source activity

Repeated readings are counted rather than listed.

  • 2× References added · Oct 13, 2026 – Oct 13, 2026
  • 1× Official description updated · Oct 13, 2026 – Oct 13, 2026

References

8 on the record

Elsewhere on this site

Microsoft
every CVE for this vendor
2021-11
what else CISA listed that month
Memory corruption
same class
CWE-119
other pages naming this weakness

Related CVEs (same products)

  • CVE-2026-80073 Microsoft Office Outlook Information Disclosure Vulnerability Sep 8, 2026
  • CVE-2026-78519 Microsoft Office Outlook Remote Code Execution Vulnerability Sep 8, 2026
  • CVE-2026-69629 Microsoft Office Outlook Remote Code Execution Vulnerability Sep 8, 2026
  • CVE-2026-70329 Integer Overflow or Wraparound in Microsoft 365 Apps Aug 11, 2026
  • CVE-2026-62882 Insufficiently Protected Credentials in Microsoft 365 Apps Aug 11, 2026
  • CVE-2026-42893 Microsoft Outlook for iOS Tampering Vulnerability May 12, 2026

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 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-2017-11774 is "Microsoft Office Outlook Security Feature Bypass Vulnerability", rated High. It affects Outlook (Microsoft); versions are in the scope table. It is in CISA KEV: there is evidence of real-world exploitation. CVSS 7.8 describes technical severity. EPSS 59.63% 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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