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CVE-2026-6791

CVE-2026-6791 · Potential stack-based buffer clash during tilde expansion in wordexp

This page contains facts from public vulnerability sources. Check the original advisory before updating.

When expanding paths that begin with a tilde (~) followed by a username, the internal parse_tilde function extracts the username to determine the user's home directory. The implementation allocates memory for this username directly on the stack using the strndupa macro. Because the size of this allocation was determined by the length of the user-supplied input without any bounds checks, passing an excessively long username e.g. thousands of characters, forces the thread to exhaust its stack space. Thus if an application passes untrusted, attacker-controlled input to the wordexp function, an attacker can trigger a stack clash.

CVSS 6.6 · Medium · EPSS 0.2% · Fix available

Published
Updated

Stack: system

Affected products and versions

  • glibc

    Versions
    • ≥ 2.0, ≤ 2.43: Affected (custom)

    No fix published

  • glibc Debian:12

    Versions
    • 2.36-10~0
    • 2.36-9
    • 2.36-9+deb12u1
    • 2.36-9+deb12u10
    • 2.36-9+deb12u11
    • 2.36-9+deb12u12
    • 2.36-9+deb12u13
    • 2.36-9+deb12u14
    • 2.36-9+deb12u2
    • 2.36-9+deb12u3
    • 2.36-9+deb12u4
    • 2.36-9+deb12u5
    • 2.36-9+deb12u6
    • 2.36-9+deb12u7
    • 2.36-9+deb12u8
    • 2.36-9+deb12u9
    • 2.36-9+loong64
    • 2.37-1
    • 2.37-10
    • 2.37-11
    • 2.37-12
    • 2.37-13
    • 2.37-14
    • 2.37-15
    • 2.37-15.1
    • 2.37-15.1+sh4
    • 2.37-15~deb13u1
    • 2.37-16
    • 2.37-17
    • 2.37-18
    • 2.37-19
    • 2.37-2
    • 2.37-3
    • 2.37-4
    • 2.37-5
    • 2.37-6
    • 2.37-7
    • 2.37-8
    • 2.37-9
    • 2.38-1
    • 2.38-10
    • 2.38-11
    • 2.38-12
    • 2.38-12.1
    • 2.38-13
    • 2.38-14
    • 2.38-15~0
    • 2.38-15~1
    • 2.38-2
    • 2.38-3
    • 2.38-4
    • 2.38-5
    • 2.38-6
    • 2.38-7
    • 2.38-7~0+hurd.1
    • 2.38-8
    • 2.38-9
    • 2.39-1
    • 2.39-2
    • 2.39-3
    • 2.39-3.1
    • 2.39-4
    • 2.39-5
    • 2.39-6
    • 2.39-6+hurd.1
    • 2.39-6+sh4
    • 2.39-7
    • 2.39-7+sh4
    • 2.39-7~0
    • 2.39-8~0
    • 2.40-1
    • 2.40-2
    • 2.40-2+sh4
    • 2.40-3
    • 2.40-3+sh4
    • 2.40-4
    • 2.40-5
    • 2.40-5~hurd.1
    • 2.40-6
    • 2.40-6~1
    • 2.40-7
    • 2.41-1
    • 2.41-10
    • 2.41-11
    • 2.41-12
    • 2.41-13~hurd.0
    • 2.41-13~hurd.1
    • 2.41-2
    • 2.41-3
    • 2.41-4
    • 2.41-4~0
    • 2.41-5
    • 2.41-5~0
    • 2.41-6
    • 2.41-7
    • 2.41-8
    • 2.41-8~0
    • 2.41-8~1
    • 2.41-9
    • 2.41-9~0
    • 2.41-9~1
    • 2.42-1
    • 2.42-10
    • 2.42-11
    • 2.42-12
    • 2.42-12~hurd.1
    • 2.42-13
    • 2.42-14
    • 2.42-14~hurd.1
    • 2.42-15
    • 2.42-15~hurd.1
    • 2.42-16
    • 2.42-17
    • 2.42-2
    • 2.42-3
    • 2.42-4
    • 2.42-5
    • 2.42-6
    • 2.42-7
    • 2.42-8
    • 2.42-8~hurd.1
    • 2.42-8~hurd.2
    • 2.42-9
    • 2.43-1
    • 2.43-2
    • 2.43-3
    • 2.43-3+m68k
    • 2.43-4
    • 2.43-4+m68k
    • 2.43-5
    • 2.43-6
    • 2.43-7
    • 2.43-7~hurd.1
    • 2.44-1
    • 2.44-2
    • 2.44-3
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • glibc Debian:13

    Versions
    • 2.41-12
    • 2.41-12+deb13u1
    • 2.41-12+deb13u2
    • 2.41-12+deb13u3
    • 2.41-12+deb13u4
    • 2.41-13~hurd.0
    • 2.41-13~hurd.1
    • 2.42-1
    • 2.42-10
    • 2.42-11
    • 2.42-12
    • 2.42-12~hurd.1
    • 2.42-13
    • 2.42-14
    • 2.42-14~hurd.1
    • 2.42-15
    • 2.42-15~hurd.1
    • 2.42-16
    • 2.42-17
    • 2.42-2
    • 2.42-3
    • 2.42-4
    • 2.42-5
    • 2.42-6
    • 2.42-7
    • 2.42-8
    • 2.42-8~hurd.1
    • 2.42-8~hurd.2
    • 2.42-9
    • 2.43-1
    • 2.43-2
    • 2.43-3
    • 2.43-3+m68k
    • 2.43-4
    • 2.43-4+m68k
    • 2.43-5
    • 2.43-6
    • 2.43-7
    • 2.43-7~hurd.1
    • 2.44-1
    • 2.44-2
    • 2.44-3
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • glibc Debian:14

    Versions
    • 2.41-12
    • 2.41-13~hurd.0
    • 2.41-13~hurd.1
    • 2.42-1
    • 2.42-10
    • 2.42-11
    • 2.42-12
    • 2.42-12~hurd.1
    • 2.42-13
    • 2.42-14
    • 2.42-14~hurd.1
    • 2.42-15
    • 2.42-15~hurd.1
    • 2.42-16
    • 2.42-17
    • 2.42-2
    • 2.42-3
    • 2.42-4
    • 2.42-5
    • 2.42-6
    • 2.42-7
    • 2.42-8
    • 2.42-8~hurd.1
    • 2.42-8~hurd.2
    • 2.42-9
    • 2.43-1
    • 2.43-2
    Affected ranges
    • ECOSYSTEM: < 2.43-3

    Update to 2.43-3

  • eglibc Ubuntu:Pro:14.04:LTS

    Versions
    • 2.17-93ubuntu4
    • 2.18-0ubuntu1
    • 2.18-0ubuntu2
    • 2.18-0ubuntu4
    • 2.18-0ubuntu5
    • 2.18-0ubuntu6
    • 2.18-0ubuntu7
    • 2.19-0ubuntu2
    • 2.19-0ubuntu3
    • 2.19-0ubuntu4
    • 2.19-0ubuntu5
    • 2.19-0ubuntu6
    • 2.19-0ubuntu6.1
    • 2.19-0ubuntu6.3
    • 2.19-0ubuntu6.4
    • 2.19-0ubuntu6.5
    • 2.19-0ubuntu6.6
    • 2.19-0ubuntu6.7
    • 2.19-0ubuntu6.8
    • 2.19-0ubuntu6.9
    • 2.19-0ubuntu6.10
    • 2.19-0ubuntu6.11
    • 2.19-0ubuntu6.13
    • 2.19-0ubuntu6.14
    • 2.19-0ubuntu6.15
    • 2.19-0ubuntu6.15+esm1
    • 2.19-0ubuntu6.15+esm2
    • 2.19-0ubuntu6.15+esm3
    • 2.19-0ubuntu6.15+esm4
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • glibc Ubuntu:Pro:16.04:LTS

    Versions
    • 2.21-0ubuntu4
    • 2.21-0ubuntu5
    • 2.21-0ubuntu6
    • 2.23-0ubuntu1
    • 2.23-0ubuntu2
    • 2.23-0ubuntu3
    • 2.23-0ubuntu4
    • 2.23-0ubuntu5
    • 2.23-0ubuntu6
    • 2.23-0ubuntu7
    • 2.23-0ubuntu9
    • 2.23-0ubuntu10
    • 2.23-0ubuntu11
    • 2.23-0ubuntu11.2
    • 2.23-0ubuntu11.3
    • 2.23-0ubuntu11.3+esm1
    • 2.23-0ubuntu11.3+esm2
    • 2.23-0ubuntu11.3+esm3
    • 2.23-0ubuntu11.3+esm5
    • 2.23-0ubuntu11.3+esm6
    • 2.23-0ubuntu11.3+esm7
    • 2.23-0ubuntu11.3+esm8
    • 2.23-0ubuntu11.3+esm9
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • glibc Ubuntu:Pro:18.04:LTS

    Versions
    • 2.26-0ubuntu2
    • 2.26-0ubuntu2.1
    • 2.27-0ubuntu2
    • 2.27-0ubuntu3
    • 2.27-3ubuntu1
    • 2.27-3ubuntu1.2
    • 2.27-3ubuntu1.3
    • 2.27-3ubuntu1.4
    • 2.27-3ubuntu1.5
    • 2.27-3ubuntu1.6
    • 2.27-3ubuntu1.6+esm1
    • 2.27-3ubuntu1.6+esm2
    • 2.27-3ubuntu1.6+esm3
    • 2.27-3ubuntu1.6+esm4
    • 2.27-3ubuntu1.6+esm5
    • 2.27-3ubuntu1.6+esm6
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • glibc Ubuntu:Pro:20.04:LTS

    Versions
    • 2.30-0ubuntu2
    • 2.30-0ubuntu3
    • 2.31-0ubuntu5
    • 2.31-0ubuntu6
    • 2.31-0ubuntu7
    • 2.31-0ubuntu9
    • 2.31-0ubuntu9.1
    • 2.31-0ubuntu9.2
    • 2.31-0ubuntu9.3
    • 2.31-0ubuntu9.7
    • 2.31-0ubuntu9.9
    • 2.31-0ubuntu9.12
    • 2.31-0ubuntu9.14
    • 2.31-0ubuntu9.15
    • 2.31-0ubuntu9.16
    • 2.31-0ubuntu9.17
    • 2.31-0ubuntu9.18
    • 2.31-0ubuntu9.18+esm1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • glibc Ubuntu:22.04:LTS

    Versions
    • 2.34-0ubuntu3
    • 2.35-0ubuntu1
    • 2.35-0ubuntu3
    • 2.35-0ubuntu3.1
    • 2.35-0ubuntu3.3
    • 2.35-0ubuntu3.4
    • 2.35-0ubuntu3.5
    • 2.35-0ubuntu3.6
    • 2.35-0ubuntu3.7
    • 2.35-0ubuntu3.8
    • 2.35-0ubuntu3.9
    • 2.35-0ubuntu3.10
    • 2.35-0ubuntu3.11
    • 2.35-0ubuntu3.12
    • 2.35-0ubuntu3.13
    • 2.35-0ubuntu3.14
    Affected ranges
    • ECOSYSTEM: < 2.35-0ubuntu3.15

    Update to 2.35-0ubuntu3.15

  • glibc Ubuntu:24.04:LTS

    Versions
    • 2.38-1ubuntu6
    • 2.38-3ubuntu1
    • 2.39-0ubuntu1
    • 2.39-0ubuntu2
    • 2.39-0ubuntu6
    • 2.39-0ubuntu8
    • 2.39-0ubuntu8.1
    • 2.39-0ubuntu8.2
    • 2.39-0ubuntu8.3
    • 2.39-0ubuntu8.4
    • 2.39-0ubuntu8.5
    • 2.39-0ubuntu8.6
    • 2.39-0ubuntu8.7
    • 2.39-0ubuntu8.8
    Affected ranges
    • ECOSYSTEM: < 2.39-0ubuntu8.9

    Update to 2.39-0ubuntu8.9

  • glibc Ubuntu:26.04:LTS

    Versions
    • 2.42-0ubuntu3
    • 2.42-2ubuntu1
    • 2.42-2ubuntu2
    • 2.42-2ubuntu4
    • 2.42-2ubuntu5
    • 2.43-2ubuntu1
    • 2.43-2ubuntu2
    • 2.43-2ubuntu2.3
    Affected ranges
    • ECOSYSTEM: < 2.43-2ubuntu2.4

    Update to 2.43-2ubuntu2.4

Original sources

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