CISA KEV High Injection

CVE-2009-0557 — Microsoft Office Object Record Corruption Vulnerability

Excel in Microsoft Office 2000 SP3, Office XP SP3, Office 2003 SP3, and Office 2004 and 2008 for Mac; Excel in 2007 Microsoft Office System SP1 and SP2; Open XML File Format Converter for Mac; Microsoft Office Excel Viewer 2003 SP3; Microsoft Office Excel Viewer; and Microsoft Office Compatibility Pack for Word, Excel, and PowerPoint 2007 File Formats SP1 and SP2 allow remote attackers to execute arbitrary code via a crafted Excel file with a malformed record object, aka "Object Record Corruption Vulnerability."

Published Jun 10, 2009 · 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

High

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 · Jun 8, 2022

How the score was calculated

Confirmed exploitation (CISA KEV)+35
EPSS 53% (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 Jun 8, 2022

EPSS FIRST

53%

ahead of 99% of scored CVEs · Oct 14, 2026

Affects

Microsoft

Office and 4 more

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

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.

Documented patch — docs.microsoft.com (NIST National Vulnerability Database)

CISA required action CISA

Apply updates per vendor instructions.

US federal deadline: Jun 22, 2022 — passed 1576 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.

Identify exposed assets running the affected vendor/product/version combinations (Microsoft Office, Microsoft Office Compatibility Pack, Microsoft Office Excel Viewer…).
Treat as emergency remediation: the CVE is in CISA KEV (confirmed exploitation).
Apply the fixed version or the patch documented under Remediation.
Exploitation requires user interaction: tighten email/web filtering and warn affected users.
EPSS ahead of 99% of scored CVEs: prioritize it in the patch queue.
Search available logs for exploit probes matching the vulnerability class (injection), errors and authentication anomalies.

Affected scope

Vendor, product and versions as the sources word them.

Vendor	Product	Versions	Status	Source
Microsoft	Office	version 2000-sp3version 2003-sp3version 2004version 2007-sp1version 2007-sp2version 2008version xp-sp3	Vulnerable	NIST National Vulnerability Database
Microsoft	Office Compatibility Pack	version 2007-sp1version 2007-sp2	Vulnerable	NIST National Vulnerability Database
Microsoft	Office Excel Viewer	versions not specified by the sourceversion 2003-sp3	Vulnerable	NIST National Vulnerability Database
Microsoft	Office Sharepoint Server	version 2007-sp1version 2007-sp2	Vulnerable	NIST National Vulnerability Database
Microsoft	Open Xml File Format Converter	versions not specified by the source	Vulnerable	NIST National Vulnerability Database

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.

Score	Version	Severity	Expl.	Impact	Scored 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	—	—	GitHub, Inc. via GitHub Security Advisories
7.8	CVSS 3.1	High	—	—	CISA-ADP via CVE Program (cve.org) e CISA ADP
9.3	CVSS 2.0	High	8.6	10.0	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-94 · Code Injection

Other CVEs with this weakness →

CISA KEV details CISA

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

Listed

Jun 8, 2022

Federal deadline

Jun 22, 2022

passed 1576 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.

EPSS over time FIRST

Oct 13, 2026 → Oct 14, 2026 · 2 reading(s) · max 53.00%

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.
Look for parameters with command/query metacharacters and unexpected child processes of the service.
Hunt retroactively in logs from before Jun 8, 2022 (KEV listing): exploitation may have started earlier.

endpoint telemetry (EDR)application logs

Timeline

What happened to this CVE, newest first.

2026
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/office, microsoft/office compatibility pack, microsoft/office excel viewer, microsoft/office sharepoint server
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
2022
Added to CISA KEV catalog
Jun 7, 2022 · CISA
2009
CVE published
Jun 10, 2009 · 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

10 on the record

docs.microsoft.com/en-us/security-updates/securitybulletins/2009/ms09-021
Patch, Vendor Advisory, vendor-advisory, x_refsource_MS, NIST National Vulnerability Database
www.cisa.gov/known-exploited-vulnerabilities-catalog
US Government Resource, NIST National Vulnerability Database
oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A5564
Broken Link, vdb-entry, signature, x_refsource_OVAL, NIST National Vulnerability Database
nvd.nist.gov/vuln/detail/CVE-2009-0557
GitHub Security Advisories
github.com/advisories/GHSA-fmc6-x6ww-78h8
GitHub Security Advisories
www.us-cert.gov/cas/techalerts/TA09-160A.html
Broken Link, Third Party Advisory, US Government Resource, third-party-advisory, x_refsource_CERT, NIST National Vulnerability Database
www.securitytracker.com/id
Broken Link, Third Party Advisory, VDB Entry, vdb-entry, x_refsource_SECTRACK, NIST National Vulnerability Database
www.vupen.com/english/advisories/2009/1540
Broken Link, vdb-entry, x_refsource_VUPEN, NIST National Vulnerability Database
www.securityfocus.com/bid/35241
Broken Link, Third Party Advisory, VDB Entry, vdb-entry, x_refsource_BID, NIST National Vulnerability Database
osvdb.org/54953
Broken Link, vdb-entry, x_refsource_OSVDB, NIST National Vulnerability Database

Elsewhere on this site

Microsoft
every CVE for this vendor

2022-06
what else CISA listed that month

Injection
same class

CWE-94
other pages naming this weakness

Related CVEs (same products)

High CVE-2026-70105 Improper Input Validation in Microsoft Microsoft 365 Aug 20, 2026
Medium CVE-2026-55054 Microsoft Excel Information Disclosure Vulnerability Jul 14, 2026
High CVE-2026-47293 Microsoft Office Click-To-Run Elevation of Privilege Vulnerability Jun 9, 2026
Medium CVE-2026-42832 Microsoft Office Spoofing Vulnerability May 12, 2026
High CVE-2026-42831 Microsoft Office Remote Code Execution Vulnerability May 12, 2026
High CVE-2026-40419 Microsoft Office Click-To-Run Elevation of Privilege 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-2009-0557 is "Microsoft Office Object Record Corruption Vulnerability", rated High. It affects Office (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 53.00% 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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