OnlyPatch
Windows Address Book

CVE-2022-26926 — Windows Address Book Remote Code Execution Vulnerability

Important CVSS 7.8 EPSS 0.02649 🔬 Patch diffed 2022-05 archive

Executive Summary

None

Overview

7.8
CVSS HIGH
Important
MS Severity
Not Exploited
MS Exploit Status
Less Likely
MS Exploit Likelihood
Category Remote Code Execution
Released May 10 2022
Last Updated May 10 2022
Publicly Disclosed No
CISA KEV Not Listed
Known Exploits None Known
EPSS Score 0.02649 — 0.84282 percentile
NVD CVSS 7.8 HIGH — matches MSRC

CVSS Vector

CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C
ATTACK VECTOR
Local
ATTACK COMPLEXITY
Low
PRIVILEGES REQUIRED
None
USER INTERACTION
Required
SCOPE
Unchanged
CONFIDENTIALITY
High
INTEGRITY
High
AVAILABILITY
High
EXPLOIT CODE MATURITY
Unproven
REMEDIATION LEVEL
Official Fix
REPORT CONFIDENCE
Confirmed
Temporal Score: 6.8

EPSS Score

0.02649
probability of exploitation in the next 30 days
0.84282 percentile - updated 2026-08-14
View on FIRST.org

Affected Products

28 affected products
Product KB Article Severity Impact Restart Required
Windows 10 for 32-bit Systems 5013963 (Security Update) Important Remote Code Execution Yes
Windows 10 for x64-based Systems 5013963 (Security Update) Important Remote Code Execution Yes
Windows 10 Version 1607 for 32-bit Systems 5013952 (Security Update) Important Remote Code Execution Yes
Windows 10 Version 1607 for x64-based Systems 5013952 (Security Update) Important Remote Code Execution Yes
Windows 10 Version 1809 for 32-bit Systems 5013941 (Security Update) Important Remote Code Execution Yes
Windows 10 Version 1809 for ARM64-based Systems 5013941 (Security Update) Important Remote Code Execution Yes
Windows 10 Version 1809 for x64-based Systems 5013941 (Security Update) Important Remote Code Execution Yes
Windows 10 Version 1909 for 32-bit Systems 5013945 (Security Update) Important Remote Code Execution Yes
Windows 10 Version 1909 for ARM64-based Systems 5013945 (Security Update) Important Remote Code Execution Yes
Windows 10 Version 1909 for x64-based Systems 5013945 (Security Update) Important Remote Code Execution Yes
Windows 10 Version 20H2 for 32-bit Systems 5013942 (Security Update) Important Remote Code Execution Yes
Windows 10 Version 20H2 for ARM64-based Systems 5013942 (Security Update) Important Remote Code Execution Yes
Windows 10 Version 21H1 for 32-bit Systems 5013942 (Security Update) Important Remote Code Execution Yes
Windows 10 Version 21H1 for ARM64-based Systems 5013942 (Security Update) Important Remote Code Execution Yes
Windows 10 Version 21H1 for x64-based Systems 5013942 (Security Update) Important Remote Code Execution Yes
Windows 10 Version 21H2 for 32-bit Systems 5013942 (Security Update) Important Remote Code Execution Yes
Windows 10 Version 21H2 for ARM64-based Systems 5013942 (Security Update) Important Remote Code Execution Yes
Windows 10 Version 21H2 for x64-based Systems 5013942 (Security Update) Important Remote Code Execution Yes
Windows 11 version 21H2 for ARM64-based Systems 5013943 (Security Update) Important Remote Code Execution Yes
Windows 11 version 21H2 for x64-based Systems 5013943 (Security Update) Important Remote Code Execution Yes
Windows 7 for 32-bit Systems Service Pack 1 5014012 (Monthly Rollup) 5013999 (Security Only) Important Remote Code Execution 5012626 Base: 7.8 Temporal: 6.8 Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C 6.1.7601.25954 Yes 5014012 5013999 Windows 7 for x64-based Systems Service Pack 1 5014012 (Monthly Rollup) 5013999 (Security Only) Important Remote Code Execution 5012626 Base: 7.8 Temporal: 6.8 Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C 6.1.7601.25954 Yes 5014012 5013999 Windows 8.1 for 32-bit systems 5014011 (Monthly Rollup) 5014001 (Security Only) Important Remote Code Execution 5012670 Base: 7.8 Temporal: 6.8 Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C 6.3.9600.20371 6.3.9600.20365 Yes 5014011 5014001 Windows 8.1 for x64-based systems 5014011 (Monthly Rollup) 5014001 (Security Only) Important Remote Code Execution 5012670 Base: 7.8 Temporal: 6.8 Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C 6.3.9600.20371 6.3.9600.20365 Yes 5014011 5014001 Windows RT 8.1 5014025 (ServicingStackUpdate) Important Remote Code Execution Yes
Windows Server 2008 for 32-bit Systems Service Pack 2 5014010 (Monthly Rollup) 5014006 (Security Only) Important Remote Code Execution 5012658 Base: 7.8 Temporal: 6.8 Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C 6.0.6003.21481 Yes 5014010 5014006 Windows Server 2008 for 32-bit Systems Service Pack 2 (Server Core installation) 5014010 (Monthly Rollup) 5014006 (Security Only) Important Remote Code Execution 5012658 Base: 7.8 Temporal: 6.8 Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C 6.0.6003.21481 Yes 5014010 5014006 Windows Server 2008 for x64-based Systems Service Pack 2 5014010 (Monthly Rollup) 5014006 (Security Only) Important Remote Code Execution 5012658 Base: 7.8 Temporal: 6.8 Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C 6.0.6003.21481 Yes 5014010 5014006 Windows Server 2008 for x64-based Systems Service Pack 2 (Server Core installation) 5014010 (Monthly Rollup) 5014006 (Security Only) Important Remote Code Execution 5012658 Base: 7.8 Temporal: 6.8 Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C 6.0.6003.21481 Yes 5014010 5014006 Windows Server 2008 R2 for x64-based Systems Service Pack 1 5014012 (Monthly Rollup) 5013999 (Security Only) Important Remote Code Execution 5012626 Base: 7.8 Temporal: 6.8 Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C 6.1.7601.25954 Yes 5014012 5013999 Windows Server 2008 R2 for x64-based Systems Service Pack 1 (Server Core installation) 5014012 (Monthly Rollup) 5013999 (Security Only) Important Remote Code Execution 5012626 Base: 7.8 Temporal: 6.8 Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C 6.1.7601.25954 Yes 5014012 5013999 Windows Server 2012 5014017 (Monthly Rollup) 5014018 (Security Only) Important Remote Code Execution 5012650 Base: 7.8 Temporal: 6.8 Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C 6.2.9200.23714 Yes 5014017 5014018 Windows Server 2012 (Server Core installation) 5014017 (Monthly Rollup) 5014018 (Security Only) Important Remote Code Execution 5012650 Base: 7.8 Temporal: 6.8 Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C 6.2.9200.23714 Yes 5014017 5014018 Windows Server 2012 R2 5014011 (Monthly Rollup) 5014001 (Security Only) Important Remote Code Execution 5012670 Base: 7.8 Temporal: 6.8 Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C 6.3.9600.20371 6.3.9600.20365 Yes 5014011 5014001 Windows Server 2012 R2 (Server Core installation) 5014011 (Monthly Rollup) 5014001 (Security Only) Important Remote Code Execution 5012670 Base: 7.8 Temporal: 6.8 Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C 6.3.9600.20371 6.3.9600.20365 Yes 5014011 5014001 Windows Server 2016 5013952 (Security Update) Important Remote Code Execution Yes
Windows Server 2016 (Server Core installation) 5013952 (Security Update) Important Remote Code Execution Yes
Windows Server 2019 5013941 (Security Update) Important Remote Code Execution Yes
Windows Server 2019 (Server Core installation) 5013941 (Security Update) Important Remote Code Execution Yes
Windows Server 2022 5013944 (Security Update) Important Remote Code Execution Yes
Windows Server 2022 (Server Core installation) 5013944 (Security Update) Important Remote Code Execution Yes
Windows Server, version 20H2 (Server Core Installation) 5013942 (Security Update) Important Remote Code Execution Yes

Patches

8 patches
Article Type Restart
5013963 Security Update Yes
5013952 Security Update Yes
5013941 Security Update Yes
5013945 Security Update Yes
5013942 Security Update Yes
5013943 Security Update Yes
5014025 ServicingStackUpdate Yes
5013944 Security Update Yes

Patch Diff

ghidriff · wab32.dll (KB5013943)

Integer-overflow heap corruption in the Windows Address Book (wab32.dll) property merge path. ScMergePropValues calls _ScCountPropsEx twice to size two property arrays (local_1c and local_20), then allocates with MAPIAllocateBuffer(local_20 + local_1c, ...) - an UNCHECKED 32-bit addition of two attacker-influenced sizes. A crafted .wab/.vcf/contact file whose two property arrays sum past 4GB wraps the total to a small value, MAPIAllocateBuffer returns an undersized buffer, and the subsequent property copy overflows the heap. The May 2022 patch routes the size addition through ULongAdd (checked add, fails on overflow) and hardens _ScCountPropsEx (gains a 4th parameter and restructured NULL/bounds handling). 32-bit binary; reached by opening or previewing a malicious address-book file. Verified by ghidriff of 10.0.19041.1110 -> .1706.

Pre-patch version 10.0.19041.1110
Post-patch version 10.0.19041.1706
Function Address Change Note
ScMergePropValues code (size addition routed through ULongAdd) PRE: local_14 = MAPIAllocateBuffer(local_20 + local_1c, &local_c) - unchecked 32-bit add of the two counted property sizes. POST: the add is replaced by ULongAdd(local_1c, local_20, &size) with the overflow branch bailing before allocation.
_ScCountPropsEx@16 code (signature + bounds handling hardened) Gains a 4th parameter (param_4 output) and restructures the NULL/param checks and the counting loop (uVar8 = *param_2 >> 0x10 ...). Produces the per-array size consumed by ScMergePropValues.
ULongAdd newly called Checked-addition helper; byte-identical itself, newly invoked from ScMergePropValues to guard the allocation size.
View full diff report View RCA report

Attack Path

Two attacker-controlled property-array sizes are summed without overflow check, producing an undersized allocation the merge then overflows

Attack path for CVE-2022-26926 Two attacker-controlled property-array sizes are summed without overflow check, producing an undersized allocation the merge then overflows 01 — ENTRY Victim opens or previews a crafted address-book file wab32.dll is the Windows Address Book. A malicious .wab / .vcf / contact file is parsed on open or preview - no privileges beyond the victim's own; delivery by mail, download or share. 02 — CONTROLLED INPUT The file defines two property arrays whose declared sizes are attacker-chosen Each array's size is derived by _ScCountPropsEx from counts and per-property sizes taken straight from the file. 03 — PATH ScMergePropValues counts both arrays, then allocates a combined buffer It calls _ScCountPropsEx twice (into local_1c and local_20) and passes local_20 + local_1c to MAPIAllocateBuffer. 04 — MISSING CHECK The two sizes are added as unchecked 32-bit integers local_20 + local_1c wraps modulo 2^32. Sizes summing just past 4GB produce a small total, so MAPIAllocateBuffer returns a buffer far smaller than the data that follows. The patch replaces the add with ULongAdd, which fails the operation on overflow, and hardens _ScCountPropsEx. 05 — PRIMITIVE Heap buffer overflow with attacker-controlled property data The merge writes both full property arrays into the undersized allocation, overrunning adjacent heap. Rated RCE by MSRC; the write contents come from the file.

Derived from the patch delta: the checks added by the vendor identify which fields crossed a trust boundary unvalidated. Reachability and privilege are taken from the call chain in the RCA report.

Known Exploits

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