CVE-2026-119602
libmspack through 0.11alpha Uninitialized Memory Disclosure via MS-ZIP Decompressor Window
libmspack through 0.11alpha contains an uninitialized memory disclosure vulnerability in the MS-ZIP decompressor that allows attackers to leak heap data via unchecked back-reference distances. Attackers can supply a crafted MS-ZIP CAB file whose first block begins with a back-reference, causing cabd->extract() to write up to 32 KiB of stale heap memory into extracted output.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- Low
- Integrity
- None
- Availability
- None
Exploit likelihood
What each source reports
CVE List Score used
6.3
libmspack through 0.11alpha Uninitialized Memory Disclosure via MS-ZIP Decompressor Window
libmspack through 0.11alpha contains an uninitialized memory disclosure vulnerability in the MS-ZIP decompressor that allows attackers to leak heap data via unchecked back-reference distances. Attackers can supply a crafted MS-ZIP CAB file whose first block begins with a back-reference, causing cabd->extract() to write up to 32 KiB of stale heap memory into extracted output.
- Record
CVE-2026-119602- CVSS 4.0
- 6.3 Medium
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N - CVSS 3.1
- 3.7 Low
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N - Weakness
- CWE-908
- Updated
- 2026-11-02
EUVDEUVD-2026-113939
6.3
libmspack through 0.11alpha contains an uninitialized memory disclosure vulnerability in the MS-ZIP decompressor that allows attackers to leak heap data via unchecked back-reference distances. Attackers can supply a crafted MS-ZIP CAB file whose first block begins with a back-reference, causing cabd->extract() to write up to 32 KiB of stale heap memory into extracted output.
- Record
EUVD-2026-113939- CVSS 4.0
- 6.3 Medium
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-xxh6-gw5r-86fm
6.3
libmspack through 0.11alpha contains an uninitialized memory disclosure vulnerability in the MS...
libmspack through 0.11alpha contains an uninitialized memory disclosure vulnerability in the MS-ZIP decompressor that allows attackers to leak heap data via unchecked back-reference distances. Attackers can supply a crafted MS-ZIP CAB file whose first block begins with a back-reference, causing cabd->extract() to write up to 32 KiB of stale heap memory into extracted output.
- Record
GHSA-xxh6-gw5r-86fm- CVSS 4.0
- 6.3 Medium
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - CVSS 3.1
- 3.7 Low
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N - Weakness
- CWE-908
- Updated
- 2026-11-02
NVD
6.3
libmspack through 0.11alpha contains an uninitialized memory disclosure vulnerability in the MS-ZIP decompressor that allows attackers to leak heap data via unchecked back-reference distances. Attackers can supply a crafted MS-ZIP CAB file whose first block begins with a back-reference, causing cabd->extract() to write up to 32 KiB of stale heap memory into extracted output.
- Record
CVE-2026-119602- CVSS 4.0
- 6.3 Medium
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - CVSS 3.1
- 3.7 Low
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N - Weakness
- CWE-908
- Updated
- 2026-11-02
OSV
6.3
libmspack through 0.11alpha Uninitialized Memory Disclosure via MS-ZIP Decompressor Window
libmspack through 0.11alpha contains an uninitialized memory disclosure vulnerability in the MS-ZIP decompressor that allows attackers to leak heap data via unchecked back-reference distances. Attackers can supply a crafted MS-ZIP CAB file whose first block begins with a back-reference, causing cabd->extract() to write up to 32 KiB of stale heap memory into extracted output.
- Record
CVE-2026-119602- CVSS 4.0
- 6.3 Medium
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N - Weakness
- CWE-908
- Updated
- 2026-11-02
OSVDEBIAN-CVE-2026-119602
6.3
libmspack through 0.11alpha contains an uninitialized memory disclosure vulnerability in the MS-ZIP decompressor that allows attackers to leak heap data via unchecked back-reference distances. Attackers can supply a crafted MS-ZIP CAB file whose first block begins with a back-reference, causing cabd->extract() to write up to 32 KiB of stale heap memory into extracted output.
- Record
DEBIAN-CVE-2026-119602- CVSS 4.0
- 6.3 Medium
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - Updated
- 2026-11-02
OSVUBUNTU-CVE-2026-119602
6.3
libmspack through 0.11alpha contains an uninitialized memory disclosure vulnerability in the MS-ZIP decompressor that allows attackers to leak heap data via unchecked back-reference distances. Attackers can supply a crafted MS-ZIP CAB file whose first block begins with a back-reference, causing cabd->extract() to write up to 32 KiB of stale heap memory into extracted output.
- Record
UBUNTU-CVE-2026-119602- CVSS 4.0
- 6.3 Medium
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N - CVSS 3.1
- 3.7 Low
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N - Updated
- 2026-11-06
OSVAZL-112667 No score
CVE-2026-119602 affecting package clamav 1.5.4-2
libmspack through 0.11alpha contains an uninitialized memory disclosure vulnerability in the MS-ZIP decompressor that allows attackers to leak heap data via unchecked back-reference distances. Attackers can supply a crafted MS-ZIP CAB file whose first block begins with a back-reference, causing cabd->extract() to write up to 32 KiB of stale heap memory into extracted output.
- Record
AZL-112667- Updated
- 2026-11-05
OSVAZL-112676 No score
CVE-2026-119602 affecting package libmspack 0.11alpha-1
libmspack through 0.11alpha contains an uninitialized memory disclosure vulnerability in the MS-ZIP decompressor that allows attackers to leak heap data via unchecked back-reference distances. Attackers can supply a crafted MS-ZIP CAB file whose first block begins with a back-reference, causing cabd->extract() to write up to 32 KiB of stale heap memory into extracted output.
- Record
AZL-112676- Updated
- 2026-11-05
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
clamavAzure Linux:3 |
through 1.5.4-2 | None known |
libmspackAzure Linux:3 |
through 0.11alpha-1 | None known |
libmspackDebian:12 |
All versions, plus listed versions 0.11-10.11-1.10.11-1.1~exp10.11-2 |
None known |
libmspackDebian:13 |
All versions, plus listed versions 0.11-1.10.11-2 |
None known |
libmspackDebian:14 |
All versions, plus listed versions 0.11-1.10.11-2 |
None known |
clamavUbuntu:Pro:14.04:LTS |
All versions, plus listed versions 0.97.8+dfsg-1ubuntu40.97.8+dfsg-1ubuntu50.98.1+dfsg-1ubuntu40.98.1+dfsg-1ubuntu50.98.1+dfsg-2ubuntu2 Show 28 moreShow less0.98.1+dfsg-4ubuntu10.98.1+dfsg-4ubuntu1.10.98.5+addedllvm-0ubuntu0.14.04.10.98.6+dfsg-0ubuntu0.14.04.10.98.7+dfsg-0ubuntu0.14.04.10.99.2+addedllvm-0ubuntu0.14.04.10.99.2+addedllvm-0ubuntu0.14.04.20.99.3+addedllvm-0ubuntu0.14.04.10.99.4+addedllvm-0ubuntu0.14.04.10.100.1+dfsg-1ubuntu0.14.04.10.100.1+dfsg-1ubuntu0.14.04.20.100.1+dfsg-1ubuntu0.14.04.30.100.1+dfsg-1ubuntu0.14.04.40.100.2+dfsg-1ubuntu0.14.04.10.100.2+dfsg-1ubuntu0.14.04.20.100.3+dfsg-0ubuntu0.14.04.10.100.3+dfsg-0ubuntu0.14.04.1+esm10.101.4+dfsg-0ubuntu0.14.04.1+esm10.102.1+dfsg-0ubuntu0.14.04.1+esm10.102.2+dfsg-0ubuntu0.14.04.1+esm10.102.3+dfsg-0ubuntu0.14.04.1+esm10.102.4+dfsg-0ubuntu0.14.04.1+esm10.103.2+dfsg-0ubuntu0.14.04.1+esm10.103.2+dfsg-0ubuntu0.14.04.1+esm20.103.5+dfsg-0ubuntu0.14.04.1+esm10.103.6+dfsg-0ubuntu0.14.04.1+esm10.103.8+dfsg-0ubuntu0.14.04.1+esm10.103.9+dfsg-0ubuntu0.14.04.1+esm1 |
None known |
libmspackUbuntu:Pro:14.04:LTS |
All versions, plus listed versions 0.4-10.4-1ubuntu0.1~esm10.4-1ubuntu0.1~esm2 |
None known |
libmspackUbuntu:16.04:LTS |
All versions, plus listed versions 0.5-10.5-1ubuntu0.16.04.10.5-1ubuntu0.16.04.20.5-1ubuntu0.16.04.30.5-1ubuntu0.16.04.4 |
None known |
libmspackUbuntu:18.04:LTS |
All versions, plus listed versions 0.6-30.6-3ubuntu0.10.6-3ubuntu0.20.6-3ubuntu0.3 |
None known |
libmspackUbuntu:20.04:LTS |
All versions, plus listed versions 0.10.1-10.10.1-2 |
None known |
Show 4 moreShow less
| Package | Affected | Fixed |
|---|---|---|
libmspackUbuntu:22.04:LTS |
All versions, plus listed versions 0.10.1-2build10.10.1-2build20.10.1-2ubuntu0.1 |
None known |
libmspackUbuntu:24.04:LTS |
All versions, plus listed versions 0.11-10.11-1.10.11-1.1build10.11-1.1ubuntu0.24.04.1 |
None known |
libmspackUbuntu:26.10 |
All versions, plus listed versions 0.11-1.1build20.11-1.1ubuntu0.26.10.1 |
None known |
libmspackUbuntu:26.04:LTS |
All versions, plus listed versions 0.11-1.1build10.11-1.1build20.11-1.1ubuntu0.26.04.1 |
None known |
History
| Recorded | Changed | Sources |
|---|---|---|
| affected, references | OSV | |
| affected, aliases, references | OSV | |
| affected, aliases, facts, references | OSV | |
| first indexed | CVE List, EUVD, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-119602 is a medium vulnerability (CVSS 6.3) in Kyz Libmspack, published October 30, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.31%, the 23rd percentile. No source names a fixed version.
References
github.com/kyz/libmspack/issues/60
github.com/kyz/libmspack/blob/v0.11alpha/libmspack/mspack/mszipd.c
hackmd.io/@haindpwn/libmspack-mszip-uninit-window-info-leak
github.com/kyz/libmspack
vulncheck.com/advisories/libmspack-through-0-11alpha-uninitialized-memory-disclosure-via-ms-zip-decompressor-window
nvd.nist.gov/vuln/detail/CVE-2026-119602