CVE-2018-18586
** DISPUTED ** chmextract.c in the chmextract sample program, as distributed with libmspack...
CVE-2018-18586 is a medium vulnerability (CVSS 5.3) in Kyzer Libmspack, published October 23, 2018. Its validity is disputed. EPSS puts the chance of exploitation in the next 30 days at 3.28%, the 88th percentile. Fixed in libmspack 0.8_alpha-r0.
chmextract.c in the chmextract sample program, as distributed with libmspack before 0.8alpha, does not protect against absolute/relative pathnames in CHM files, leading to Directory Traversal. NOTE: the vendor disputes that this is a libmspack vulnerability, because chmextract.c was only intended as a source-code example, not a supported application
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
NVD Score used
5.3
chmextract.c in the chmextract sample program, as distributed with libmspack before 0.8alpha, does not protect against absolute/relative pathnames in CHM files, leading to Directory Traversal. NOTE: the vendor disputes that this is a libmspack vulnerability, because chmextract.c was only intended as a source-code example, not a supported application
- Record
CVE-2018-18586- CVSS 3.0
- 5.3 Medium
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N - CVSS 2.0
- 5.0 Medium
AV:N/AC:L/Au:N/C:P/I:N/A:N - Weakness
- CWE-22
- Updated
- 2026-11-02
CVE List No score
chmextract.c in the chmextract sample program, as distributed with libmspack before 0.8alpha, does not protect against absolute/relative pathnames in CHM files, leading to Directory Traversal. NOTE: the vendor disputes that this is a libmspack vulnerability, because chmextract.c was only intended as a source-code example, not a supported application
- Record
CVE-2018-18586- Updated
- 2026-11-02
EUVDEUVD-2018-10306 No score
chmextract.c in the chmextract sample program, as distributed with libmspack before 0.8alpha, does not protect against absolute/relative pathnames in CHM files, leading to Directory Traversal. NOTE: the vendor disputes that this is a libmspack vulnerability, because chmextract.c was only intended as a source-code example, not a supported application
- Record
EUVD-2018-10306- Updated
- 2026-11-03
GitHub AdvisoriesGHSA-jcvf-2rhc-m6h8
5.3
** DISPUTED ** chmextract.c in the chmextract sample program, as distributed with libmspack...
** DISPUTED ** chmextract.c in the chmextract sample program, as distributed with libmspack before 0.8alpha, does not protect against absolute/relative pathnames in CHM files, leading to Directory Traversal. NOTE: the vendor disputes that this is a libmspack vulnerability, because chmextract.c was only intended as a source-code example, not a supported application.
- Record
GHSA-jcvf-2rhc-m6h8- CVSS 3.0
- 5.3 Medium
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N - Weakness
- CWE-22
- Updated
- 2026-11-02
OSVALPINE-CVE-2018-18586
5.3
chmextract.c in the chmextract sample program, as distributed with libmspack before 0.8alpha, does not protect against absolute/relative pathnames in CHM files, leading to Directory Traversal. NOTE: the vendor disputes that this is a libmspack vulnerability, because chmextract.c was only intended as a source-code example, not a supported application
- Record
ALPINE-CVE-2018-18586- CVSS 3.0
- 5.3 Medium
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N - Updated
- 2026-11-02
OSV
5.3
chmextract.c in the chmextract sample program, as distributed with libmspack before 0.8alpha, does not protect against absolute/relative pathnames in CHM files, leading to Directory Traversal. NOTE: the vendor disputes that this is a libmspack vulnerability, because chmextract.c was only intended as a source-code example, not a supported application
- Record
CVE-2018-18586- CVSS 3.0
- 5.3 Medium
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N - Updated
- 2026-11-02
Show 7 moreShow less
OSVDEBIAN-CVE-2018-18586
5.3
chmextract.c in the chmextract sample program, as distributed with libmspack before 0.8alpha, does not protect against absolute/relative pathnames in CHM files, leading to Directory Traversal. NOTE: the vendor disputes that this is a libmspack vulnerability, because chmextract.c was only intended as a source-code example, not a supported application
- Record
DEBIAN-CVE-2018-18586- CVSS 3.0
- 5.3 Medium
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N - Updated
- 2026-11-02
OSVMGASA-2018-0455 No score
Updated libmspack/cabextract packages fix security vulnerabilities
Hanno Böck discovered that libmspack incorrectly handled certain CHM files. An attacker could possibly use this issue to cause a denial of service (CVE-2018-14679, CVE-2018-14680).
Jakub Wilk discovered that libmspack incorrectly handled certain KWAJ files. An attacker could possibly use this issue to execute arbitrary code (CVE-2018-14681).
Dmitry Glavatskikh discovered that libmspack incorrectly certain CHM files. An attacker could possibly use this issue to execute arbitrary code (CVE-2018-14682).
If a CAB file has a Quantum-compressed datablock with exactly 38912 compressed bytes, cabextract would write exactly one byte beyond its input buffer (CVE-2018-18584).
libmspack didn't reject blank CHM filenames that are blank because they have embedded null bytes, not just because they are zero-length (CVE-2018-18585).
chmextract didn't protect from absolute/relative pathnames in CHM files (CVE-2018-18586).
- Record
MGASA-2018-0455- Updated
- 2026-11-02
OSVopenSUSE-SU-2022:0069-1 No score
Security update for libmspack
This update for libmspack fixes the following issues:
- CVE-2018-18586: Fixed directory traversal in chmextract by adding anti '../' and leading slash protection (bsc#1113040).
- Record
openSUSE-SU-2022:0069-1- Updated
- 2026-11-02
OSVopenSUSE-SU-2024:13619-1 No score
libmspack-devel-0.11-2.1 on GA media
These are all security issues fixed in the libmspack-devel-0.11-2.1 package on the GA media of openSUSE Tumbleweed.
- Record
openSUSE-SU-2024:13619-1- Updated
- 2026-11-02
OSVSUSE-SU-2022:0069-1 No score
Security update for libmspack
This update for libmspack fixes the following issues:
- CVE-2018-18586: Fixed directory traversal in chmextract by adding anti '../' and leading slash protection (bsc#1113040).
- Record
SUSE-SU-2022:0069-1- Updated
- 2026-11-02
OSVSUSE-SU-2022:0069-2 No score
Security update for libmspack
This update for libmspack fixes the following issues:
- CVE-2018-18586: Fixed directory traversal in chmextract by adding anti '../' and leading slash protection (bsc#1113040).
- Record
SUSE-SU-2022:0069-2- Updated
- 2026-11-02
OSVSUSE-SU-2022:4287-1 No score
Security update for libmspack
This update for libmspack fixes the following issues:
- CVE-2018-18586: Add leading slash protection to chmextract. (bsc#1113040)
- Record
SUSE-SU-2022:4287-1- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
libmspackAlpine:v3.10 |
before 0.8_alpha-r0 | 0.8_alpha-r0 |
libmspackAlpine:v3.11 |
before 0.8_alpha-r0 | 0.8_alpha-r0 |
libmspackAlpine:v3.6 |
before 0.8_alpha-r0 | 0.8_alpha-r0 |
libmspackAlpine:v3.7 |
before 0.8_alpha-r0 | 0.8_alpha-r0 |
libmspackAlpine:v3.8 |
before 0.8_alpha-r0 | 0.8_alpha-r0 |
libmspackAlpine:v3.9 |
before 0.8_alpha-r0 | 0.8_alpha-r0 |
libmspackDebian:12 |
before 0.8-1 | 0.8-1 |
libmspackDebian:13 |
before 0.8-1 | 0.8-1 |
libmspackDebian:14 |
before 0.8-1 | 0.8-1 |
libmspackMageia:6 |
before 0.9.1-0.alpha.1.mga6 | 0.9.1-0.alpha.1.mga6 |
Show 9 moreShow less
| Package | Affected | Fixed |
|---|---|---|
cabextractMageia:6 |
before 1.9-1.mga6 | 1.9-1.mga6 |
libmspackSUSE:Linux Enterprise Module for Basesystem 15 SP3 |
before 0.6-3.14.1 | 0.6-3.14.1 |
libmspackSUSE:Linux Enterprise Micro 5.0 |
before 0.6-3.14.1 | 0.6-3.14.1 |
libmspackSUSE:Linux Enterprise Micro 5.1 |
before 0.6-3.14.1 | 0.6-3.14.1 |
libmspackSUSE:Linux Enterprise Real Time 15 SP2 |
before 0.6-3.14.1 | 0.6-3.14.1 |
libmspackSUSE:Linux Enterprise Software Development Kit 12 SP5 |
before 0.4-15.13.1 | 0.4-15.13.1 |
libmspackSUSE:Linux Enterprise Server 12 SP5 |
before 0.4-15.13.1 | 0.4-15.13.1 |
libmspackSUSE:Linux Enterprise Server for SAP Applications 12 SP5 |
before 0.4-15.13.1 | 0.4-15.13.1 |
libmspackopenSUSE:Leap 15.3 |
before 0.6-3.14.1 | 0.6-3.14.1 |
History
| When | Changed | Sources |
|---|---|---|
| 2026-11-03 | aliases | EUVD |
| 2026-11-02 | created | CVE List, GitHub Advisories, NVD, OSV |
References
github.com/kyz/libmspack/commit/7cadd489698be117c47efcadd742651594429e6d
openwall.com/lists/oss-security/2018/10/22/1
bugs.debian.org/911639
security.gentoo.org/glsa/201903-20
nvd.nist.gov/vuln/detail/CVE-2018-18586
github.com/advisories/GHSA-jcvf-2rhc-m6h8
Show 15 moreShow less
security.alpinelinux.org/vuln/CVE-2018-18586
security-tracker.debian.org/tracker/CVE-2018-18586
advisories.mageia.org/MGASA-2018-0455.html
bugs.mageia.org/show_bug.cgi?id=23365
usn.ubuntu.com/3728-1
openwall.com/lists/oss-security/2018/10/23/11
suse.com/support/update/announcement/2022/suse-su-20220069-1
bugzilla.suse.com/1113040
suse.com/security/cve/CVE-2018-18586
suse.com/support/update/announcement/2022/suse-su-20220069-2
suse.com/support/update/announcement/2022/suse-su-20224287-1
lists.opensuse.org/archives/list/[email protected]/thread/IRYD4Y2CDUYSBVQUIDXTTBL6H6XYW54G
suse.com/security/cve/CVE-2018-18584
suse.com/security/cve/CVE-2018-18585
suse.com/security/cve/CVE-2019-1010305