Every CVE Search/ Get API key

CVE-2026-18508

Tar: tar: --one-top-level hardlink targets not confined to top-level directory enabling arbitrary file overwrite

4.4 MediumFix available

A flaw was found in GNU tar. When extracting an archive with the --one-top-level option, hardlink targets are not confined to the designated top-level directory and may resolve relative to the extraction working directory. A crafted archive can create hardlinks that escape the intended boundary and, when combined with a preexisting symbolic link under the working directory, may allow writing outside that boundary during a single extraction.

Attack profile

How easy it is to exploit

Attack vector
Local
Complexity
Low
Privileges needed
None
User interaction
Required

What an attacker can affect

Confidentiality
Low
Integrity
Low
Availability
None

Exploit likelihood

0.14%Unchanged since Aug 4, 2026
90%50%10%1%

What each source reports

CVE List Score used 4.4

Tar: tar: --one-top-level hardlink targets not confined to top-level directory enabling arbitrary file overwrite

A flaw was found in GNU tar. When extracting an archive with the --one-top-level option, hardlink targets are not confined to the designated top-level directory and may resolve relative to the extraction working directory. A crafted archive can create hardlinks that escape the intended boundary and, when combined with a preexisting symbolic link under the working directory, may allow writing outside that boundary during a single extraction.

Record
CVE-2026-18508
CVSS 3.1
4.4 MediumCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N
Weakness
CWE-59
Updated
2026-11-05
EUVDEUVD-2026-52327 4.4

A flaw was found in GNU tar. When extracting an archive with the --one-top-level option, hardlink targets are not confined to the designated top-level directory and may resolve relative to the extraction working directory. A crafted archive can create hardlinks that escape the intended boundary and, when combined with a preexisting symbolic link under the working directory, may allow writing outside that boundary during a single extraction.

Record
EUVD-2026-52327
CVSS 3.1
4.4 MediumCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N
Updated
2026-11-05
GitHub AdvisoriesGHSA-4f5j-wqjr-hx49 4.4

A flaw was found in GNU tar. When extracting an archive with the --one-top-level option, hardlink...

A flaw was found in GNU tar. When extracting an archive with the --one-top-level option, hardlink targets are not confined to the designated top-level directory and may resolve relative to the extraction working directory. A crafted archive can create hardlinks that escape the intended boundary and, when combined with a preexisting symbolic link under the working directory, may allow writing outside that boundary during a single extraction.

Record
GHSA-4f5j-wqjr-hx49
CVSS 3.1
4.4 MediumCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N
Weakness
CWE-59
Updated
2026-11-02
NVD 4.4

A flaw was found in GNU tar. When extracting an archive with the --one-top-level option, hardlink targets are not confined to the designated top-level directory and may resolve relative to the extraction working directory. A crafted archive can create hardlinks that escape the intended boundary and, when combined with a preexisting symbolic link under the working directory, may allow writing outside that boundary during a single extraction.

Record
CVE-2026-18508
CVSS 3.1
4.4 MediumCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N
Weakness
CWE-59
Updated
2026-11-05
OSVDEBIAN-CVE-2026-18508 4.4

A flaw was found in GNU tar. When extracting an archive with the --one-top-level option, hardlink targets are not confined to the designated top-level directory and may resolve relative to the extraction working directory. A crafted archive can create hardlinks that escape the intended boundary and, when combined with a preexisting symbolic link under the working directory, may allow writing outside that boundary during a single extraction.

Record
DEBIAN-CVE-2026-18508
CVSS 3.1
4.4 MediumCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N
Updated
2026-11-02
OSVOESA-2026-3911 4.4

tar security update

GNU Tar provides the ability to create tar archives, as well as various other kinds of manipulation. For example, you can use Tar on previously created archives to extract files, to store additional files, or to update or list files which were already stored.

Security Fix(es):

A flaw was found in GNU tar. When extracting an archive with the --one-top-level option, hardlink targets are not confined to the designated top-level directory and may resolve relative to the extraction working directory. A crafted archive can create hardlinks that escape the intended boundary and, when combined with a preexisting symbolic link under the working directory, may allow writing outside that boundary during a single extraction.(CVE-2026-18508)

Record
OESA-2026-3911
CVSS 3.1
4.4 MediumCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N
Updated
2026-11-02
Show 17 moreShow less
OSVOESA-2026-3912 4.4

tar security update

GNU Tar provides the ability to create tar archives, as well as various other kinds of manipulation. For example, you can use Tar on previously created archives to extract files, to store additional files, or to update or list files which were already stored.

Security Fix(es):

A flaw was found in GNU tar. When extracting an archive with the --one-top-level option, hardlink targets are not confined to the designated top-level directory and may resolve relative to the extraction working directory. A crafted archive can create hardlinks that escape the intended boundary and, when combined with a preexisting symbolic link under the working directory, may allow writing outside that boundary during a single extraction.(CVE-2026-18508)

Record
OESA-2026-3912
CVSS 3.1
4.4 MediumCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N
Updated
2026-11-02
OSVOESA-2026-4081 4.4

tar security update

GNU Tar provides the ability to create tar archives, as well as various other kinds of manipulation. For example, you can use Tar on previously created archives to extract files, to store additional files, or to update or list files which were already stored.

Security Fix(es):

A flaw was found in GNU tar. When extracting an archive with the --one-top-level option, hardlink targets are not confined to the designated top-level directory and may resolve relative to the extraction working directory. A crafted archive can create hardlinks that escape the intended boundary and, when combined with a preexisting symbolic link under the working directory, may allow writing outside that boundary during a single extraction.(CVE-2026-18508)

Record
OESA-2026-4081
CVSS 3.1
4.4 MediumCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N
Updated
2026-11-02
OSVRHSA-2026:50807 4.4

Red Hat Security Advisory: Red Hat Hardened Images RPMs bug fix and enhancement update

Record
RHSA-2026:50807
CVSS 3.1
4.4 MediumCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N
Updated
2026-11-02
OSVRHSA-2026:61581 5.0

Red Hat Security Advisory: tar security, bug fix, and enhancement update

Record
RHSA-2026:61581
CVSS 3.1
5.0 MediumCVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:N/I:H/A:N
Updated
2026-11-02
OSVRHSA-2026:61586 5.0

Red Hat Security Advisory: tar security, bug fix, and enhancement update

Record
RHSA-2026:61586
CVSS 3.1
5.0 MediumCVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:N/I:H/A:N
Updated
2026-11-02
OSVRHSA-2026:70390 5.6

Red Hat Security Advisory: tar security, bug fix, and enhancement update

Record
RHSA-2026:70390
CVSS 3.1
5.6 MediumCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L
Updated
2026-11-02
OSVRLSA-2026:61581 5.0

Moderate: tar security, bug fix, and enhancement update

The GNU tar program can save multiple files in an archive and restore files from an archive.

Security Fix(es):

  • tar: tar: Hidden file injection via crafted archives (CVE-2026-5704)

  • tar: tar: TOCTOU in incremental dumpdir 'X' rename handling allows restore path escape (CVE-2026-18477)

  • tar: tar: --one-top-level hardlink targets not confined to top-level directory enabling arbitrary file overwrite (CVE-2026-18508)

Bug Fix(es) and Enhancement(s):

  • tar: --one-top-level with absolute path fails [rhel-9] (JIRA:Rocky Linux-144021)

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

Record
RLSA-2026:61581
CVSS 3.1
5.0 MediumCVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:N/I:H/A:N
Updated
2026-11-02
OSVRLSA-2026:61586 5.0

Moderate: tar security, bug fix, and enhancement update

The GNU tar program can save multiple files in an archive and restore files from an archive.

Security Fix(es):

  • tar: tar: Hidden file injection via crafted archives (CVE-2026-5704)

  • tar: tar: TOCTOU in incremental dumpdir 'X' rename handling allows restore path escape (CVE-2026-18477)

  • tar: tar: --one-top-level hardlink targets not confined to top-level directory enabling arbitrary file overwrite (CVE-2026-18508)

Bug Fix(es) and Enhancement(s):

  • tar: --one-top-level with absolute path fails (JIRA:Rocky Linux-143906)

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

Record
RLSA-2026:61586
CVSS 3.1
5.0 MediumCVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:N/I:H/A:N
Updated
2026-11-02
OSVRLSA-2026:70390 5.6

Moderate: tar security, bug fix, and enhancement update

The GNU tar program can save multiple files in an archive and restore files from an archive.

Security Fix(es):

  • tar: Tar path traversal (CVE-2025-45582)

  • tar: tar: Hidden file injection via crafted archives (CVE-2026-5704)

  • tar: tar: TOCTOU in incremental dumpdir 'X' rename handling allows restore path escape (CVE-2026-18477)

  • tar: tar: --one-top-level hardlink targets not confined to top-level directory enabling arbitrary file overwrite (CVE-2026-18508)

Bug Fix(es) and Enhancement(s):

  • tar: --one-top-level with absolute path fails [rhel-8.10.z] (JIRA:Rocky Linux-144019)

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

Record
RLSA-2026:70390
CVSS 3.1
5.6 MediumCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L
Updated
2026-11-02
OSVUBUNTU-CVE-2026-18508 4.4

A flaw was found in GNU tar. When extracting an archive with the --one-top-level option, hardlink targets are not confined to the designated top-level directory and may resolve relative to the extraction working directory. A crafted archive can create hardlinks that escape the intended boundary and, when combined with a preexisting symbolic link under the working directory, may allow writing outside that boundary during a single extraction.

Record
UBUNTU-CVE-2026-18508
CVSS 3.1
4.4 MediumCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N
Updated
2026-11-02
OSVALSA-2026:61581 No score

Moderate: tar security, bug fix, and enhancement update

The GNU tar program can save multiple files in an archive and restore files from an archive.

Security Fix(es):

  • tar: tar: Hidden file injection via crafted archives (CVE-2026-5704)
  • tar: tar: TOCTOU in incremental dumpdir 'X' rename handling allows restore path escape (CVE-2026-18477)
  • tar: tar: --one-top-level hardlink targets not confined to top-level directory enabling arbitrary file overwrite (CVE-2026-18508)

Bug Fix(es) and Enhancement(s):

  • tar: --one-top-level with absolute path fails [almalinux-9] (JIRA:AlmaLinux-144021)

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

Record
ALSA-2026:61581
Updated
2026-11-02
OSVALSA-2026:61586 No score

Moderate: tar security, bug fix, and enhancement update

The GNU tar program can save multiple files in an archive and restore files from an archive.

Security Fix(es):

  • tar: tar: Hidden file injection via crafted archives (CVE-2026-5704)
  • tar: tar: TOCTOU in incremental dumpdir 'X' rename handling allows restore path escape (CVE-2026-18477)
  • tar: tar: --one-top-level hardlink targets not confined to top-level directory enabling arbitrary file overwrite (CVE-2026-18508)

Bug Fix(es) and Enhancement(s):

  • tar: --one-top-level with absolute path fails (JIRA:AlmaLinux-143906)

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

Record
ALSA-2026:61586
Updated
2026-11-02
OSVALSA-2026:70390 No score

Moderate: tar security, bug fix, and enhancement update

The GNU tar program can save multiple files in an archive and restore files from an archive.

Security Fix(es):

  • tar: Tar path traversal (CVE-2025-45582)
  • tar: tar: Hidden file injection via crafted archives (CVE-2026-5704)
  • tar: tar: TOCTOU in incremental dumpdir 'X' rename handling allows restore path escape (CVE-2026-18477)
  • tar: tar: --one-top-level hardlink targets not confined to top-level directory enabling arbitrary file overwrite (CVE-2026-18508)

Bug Fix(es) and Enhancement(s):

  • tar: --one-top-level with absolute path fails [almalinux-8.10.z] (JIRA:AlmaLinux-144019)

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

Record
ALSA-2026:70390
Updated
2026-11-02
OSVAZL-94599 No score

CVE-2026-18508 affecting package tar 1.35-3

A flaw was found in GNU tar. When extracting an archive with the --one-top-level option, hardlink targets are not confined to the designated top-level directory and may resolve relative to the extraction working directory. A crafted archive can create hardlinks that escape the intended boundary and, when combined with a preexisting symbolic link under the working directory, may allow writing outside that boundary during a single extraction.

Record
AZL-94599
Updated
2026-11-05
OSVCLSA-2026-1789128477 No score

tar: Fix of CVE-2026-18508

  • CVE-2026-18508: confine hard link targets to the --one-top-level directory, so a crafted archive can no longer alias a file outside it; this also repairs extraction of legitimate hard links under --one-top-level
Record
CLSA-2026-1789128477
Updated
2026-11-02
OSVCLSA-2026-1789131413 No score

tar: Fix of CVE-2026-18508

  • CVE-2026-18508: confine hard link targets to the --one-top-level directory, so a crafted archive can no longer alias a file outside it; this also repairs extraction of legitimate hard links under --one-top-level
Record
CLSA-2026-1789131413
Updated
2026-11-02
OSVMGASA-2026-0401 No score

Updated tar packages fix security vulnerabilities

GNU Tar through 1.35 allows file overwrite via directory traversal in crafted TAR archives, with a certain two-step process. (CVE-2025-45582) Tar: toctou in incremental dumpdir 'x' rename handling allows restore path escape. (CVE-2026-18477) Tar: --one-top-level hardlink targets not confined to top-level directory enabling arbitrary file overwrite. (CVE-2026-18508)

Record
MGASA-2026-0401
Updated
2026-11-02

Affected products

Show 1 moreShow less

Affected packages

Affected packages
PackageAffectedFixed
tar
AlmaLinux:9
From an advisory covering 3 CVEs
 before 2:1.34-13.el9_8
2:1.34-13.el9_8
tar
AlmaLinux:10
From an advisory covering 3 CVEs
 before 2:1.35-13.el10_2
2:1.35-13.el10_2
tar
AlmaLinux:8
From an advisory covering 4 CVEs
 before 2:1.30-13.el8_10
2:1.30-13.el8_10
tar
Azure Linux:3
 through 1.35-3 None known
tar
TuxCare:AlmaLinux:9.2
 before 2:1.34-7.el9.tuxcare.els5
2:1.34-7.el9.tuxcare.els5
tar
TuxCare:AlmaLinux:9.6
 before 2:1.34-7.el9.tuxcare.els5
2:1.34-7.el9.tuxcare.els5
tar
Debian:12
 All versions, plus listed versions
1.34+dfsg-1.21.34+dfsg-1.2+deb12u11.34+dfsg-1.31.34+dfsg-1.41.35+dfsg-1
Show 8 moreShow less
1.35+dfsg-21.35+dfsg-31.35+dfsg-3.11.35+dfsg-41.35+dfsg-51.35+dfsg-5+hurd.11.35+dfsg-61.35+dfsg-7
 None known
tar
Debian:13
 All versions, plus listed versions
1.35+dfsg-3.11.35+dfsg-41.35+dfsg-51.35+dfsg-5+hurd.11.35+dfsg-61.35+dfsg-7
 None known
tar
Debian:14
 All versions, plus listed versions
1.35+dfsg-3.11.35+dfsg-41.35+dfsg-51.35+dfsg-5+hurd.11.35+dfsg-61.35+dfsg-7
 None known
tar
Mageia:10
From an advisory covering 3 CVEs
 before 1.35-4.1.mga10
1.35-4.1.mga10
Show 25 moreShow less
Affected packages
PackageAffectedFixed
tar
Mageia:9
From an advisory covering 3 CVEs
 before 1.35-4.1.mga9
1.35-4.1.mga9
tar
openEuler:24.03-LTS-SP1
 before 1.35-8.oe2403sp1
1.35-8.oe2403sp1
tar
openEuler:24.03-LTS-SP3
 before 1.35-8.oe2403sp3
1.35-8.oe2403sp3
tar
openEuler:24.03-LTS-SP4
 before 1.35-8.oe2403sp4
1.35-8.oe2403sp4
tar
Red Hat:hummingbird:1
 before 0:1.35-9.2.hum1
0:1.35-9.2.hum1
tar
Red Hat:enterprise_linux:9::baseos
From an advisory covering 3 CVEs
 before 2:1.34-13.el9_8
2:1.34-13.el9_8
tar-debuginfo
Red Hat:enterprise_linux:9::baseos
From an advisory covering 3 CVEs
 before 2:1.34-13.el9_8
2:1.34-13.el9_8
tar-debugsource
Red Hat:enterprise_linux:9::baseos
From an advisory covering 3 CVEs
 before 2:1.34-13.el9_8
2:1.34-13.el9_8
tar
Red Hat:enterprise_linux:10.2
From an advisory covering 3 CVEs
 before 2:1.35-13.el10_2
2:1.35-13.el10_2
tar-debuginfo
Red Hat:enterprise_linux:10.2
From an advisory covering 3 CVEs
 before 2:1.35-13.el10_2
2:1.35-13.el10_2
tar-debugsource
Red Hat:enterprise_linux:10.2
From an advisory covering 3 CVEs
 before 2:1.35-13.el10_2
2:1.35-13.el10_2
tar
Red Hat:enterprise_linux:8::baseos
From an advisory covering 4 CVEs
 before 2:1.30-13.el8_10
2:1.30-13.el8_10
tar-debuginfo
Red Hat:enterprise_linux:8::baseos
From an advisory covering 4 CVEs
 before 2:1.30-13.el8_10
2:1.30-13.el8_10
tar-debugsource
Red Hat:enterprise_linux:8::baseos
From an advisory covering 4 CVEs
 before 2:1.30-13.el8_10
2:1.30-13.el8_10
tar
Rocky Linux:9
From an advisory covering 3 CVEs
 before 2:1.34-13.el9_8
2:1.34-13.el9_8
tar
Rocky Linux:10
From an advisory covering 3 CVEs
 before 2:1.35-13.el10_2
2:1.35-13.el10_2
tar
Rocky Linux:8
From an advisory covering 4 CVEs
 before 2:1.30-13.el8_10
2:1.30-13.el8_10
tar
Ubuntu:Pro:14.04:LTS
 All versions, plus listed versions
1.26+dfsg-81.27-31.27-41.27.1-11.27.1-1ubuntu0.1
Show 7 moreShow less
1.27.1-1ubuntu0.1+esm11.27.1-1ubuntu0.1+esm21.27.1-1ubuntu0.1+esm31.27.1-1ubuntu0.1+esm41.27.1-1ubuntu0.1+esm51.27.1-1ubuntu0.1+esm61.27.1-1ubuntu0.1+esm7
 None known
tar
Ubuntu:Pro:16.04:LTS
 All versions, plus listed versions
1.27.1-21.28-2ubuntu11.28-2.11.28-2.1ubuntu0.11.28-2.1ubuntu0.2
Show 6 moreShow less
1.28-2.1ubuntu0.2+esm11.28-2.1ubuntu0.2+esm21.28-2.1ubuntu0.2+esm31.28-2.1ubuntu0.2+esm41.28-2.1ubuntu0.2+esm51.28-2.1ubuntu0.2+esm6
 None known
tar
Ubuntu:Pro:18.04:LTS
 All versions, plus listed versions
1.29b-21.29b-2ubuntu0.11.29b-2ubuntu0.21.29b-2ubuntu0.31.29b-2ubuntu0.4
Show 4 moreShow less
1.29b-2ubuntu0.4+esm11.29b-2ubuntu0.4+esm21.29b-2ubuntu0.4+esm31.29b-2ubuntu0.4+esm4
 None known
tar
Ubuntu:Pro:20.04:LTS
 All versions, plus listed versions
1.30+dfsg-61.30+dfsg-71.30+dfsg-7ubuntu0.20.04.11.30+dfsg-7ubuntu0.20.04.21.30+dfsg-7ubuntu0.20.04.3
Show 4 moreShow less
1.30+dfsg-7ubuntu0.20.04.41.30+dfsg-7ubuntu0.20.04.4+esm11.30+dfsg-7ubuntu0.20.04.4+esm21.30+dfsg-7ubuntu0.20.04.4+esm3
 None known
tar
Ubuntu:22.04:LTS
 All versions, plus listed versions
1.34+dfsg-1build11.34+dfsg-1build21.34+dfsg-1build31.34+dfsg-1ubuntu0.1.22.04.11.34+dfsg-1ubuntu0.1.22.04.2
Show 4 moreShow less
1.34+dfsg-1ubuntu0.1.22.04.31.34+dfsg-1ubuntu0.1.22.04.41.34+dfsg-1ubuntu0.1.22.04.51.34+dfsg-1ubuntu0.1.22.04.6
 None known
tar
Ubuntu:24.04:LTS
 All versions, plus listed versions
1.34+dfsg-1.2ubuntu11.34+dfsg-1.2ubuntu21.34+dfsg-1.3ubuntu11.34+dfsg-1.41.35+dfsg-2~build1
Show 7 moreShow less
1.35+dfsg-21.35+dfsg-31.35+dfsg-3build11.35+dfsg-3ubuntu0.11.35+dfsg-3ubuntu0.21.35+dfsg-3ubuntu0.31.35+dfsg-3ubuntu0.4
 None known
tar
Ubuntu:26.10
 All versions, plus listed versions
1.35+dfsg-41.35+dfsg-5ubuntu1
 None known
tar
Ubuntu:26.04:LTS
 All versions, plus listed versions
1.35+dfsg-3.1build11.35+dfsg-3.1build21.35+dfsg-41.35+dfsg-4ubuntu0.11.35+dfsg-4ubuntu0.21.35+dfsg-4ubuntu0.31.35+dfsg-4ubuntu0.4
 None known

History

History
RecordedChangedSources
affectedCVE List, EUVD, NVD
factsOSV
first indexedCVE List, EUVD, GitHub Advisories, NVD, OSV

Dates are when Every CVE recorded each change. Upstream dates may differ.

In short

CVE-2026-18508 is a medium vulnerability (CVSS 4.4) in Gnu Tar, published August 3, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.14%, the 3rd percentile. Fixed in tar 2:1.34-7.el9.tuxcare.els5.

References

Show 47 moreShow less
Pages All vulnerabilities Browse Docs Sources Guide Get API key
MoveEnter Open