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10 vulnerabilities found for erlang\/ssh by erlang
CVE-2026-48859 (GCVE-0-2026-48859)
Vulnerability from nvd – Published: 2026-06-10 14:35 – Updated: 2026-06-11 04:45
VLAI
Title
SSH server timing side-channel in ssh_auth:check_password/3 allows unauthenticated username enumeration
Summary
Observable Timing Discrepancy vulnerability in Erlang/OTP ssh (ssh_auth, ssh_options modules) allows unauthenticated remote username enumeration via timing side-channel in password authentication.
When the SSH daemon is configured with the user_passwords or password option, ssh_auth:check_password/3 performs a PBKDF2-SHA256 computation with 600,000 iterations (~300ms) for valid usernames, but returns immediately (~0ms) for invalid usernames via the ssh_options:get_password_option/2 path. This timing difference is detectable in a single authentication attempt and allows an unauthenticated attacker to distinguish valid from invalid usernames.
The user_passwords and password options are documented as intended for test purposes; the recommended alternative is pwdfun, which is not affected by this vulnerability.
This vulnerability is associated with program files lib/ssh/src/ssh_auth.erl and lib/ssh/src/ssh_options.erl.
This issue affects OTP from OTP 29.0 before 29.0.2 corresponding to ssh from 6.0 before 6.0.1.
Severity
SSVC
Exploitation: none
Automatable: yes
Technical Impact: partial
CISA Coordinator (v2.0.3)
CWE
- CWE-208 - Observable Timing Discrepancy
Assigner
References
5 references
| URL | Tags |
|---|---|
| https://github.com/erlang/otp/security/advisories… | vendor-advisoryrelated |
| https://cna.erlef.org/cves/CVE-2026-48859.html | related |
| https://osv.dev/vulnerability/EEF-CVE-2026-48859 | related |
| https://www.erlang.org/doc/system/versions.html#o… | x_version-scheme |
| https://github.com/erlang/otp/commit/c342092ef4b3… | patch |
Impacted products
2 products
Credits
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CVE-2026-48855 (GCVE-0-2026-48855)
Vulnerability from nvd – Published: 2026-06-10 14:35 – Updated: 2026-06-11 04:45
VLAI
Title
SFTP READLINK Leaks Absolute Backend Filesystem Path When Root Is Configured
Summary
Exposure of Sensitive Information to an Unauthorized Actor vulnerability in Erlang OTP ssh (ssh_sftpd module) allows File Discovery.
The SSH_FXP_READLINK handler in ssh_sftpd sends the raw result of file:read_link/2 to the client without calling chroot_filename/2 to strip the backend root prefix. An authenticated SFTP client can create a symlink inside the chroot pointing to /; ssh_sftpd resolves the target to the absolute backend root and stores it on disk. Reading the symlink back via SSH_FXP_READLINK returns that absolute path, for example /data/sftp, instead of the chrooted value /.
The information disclosed is the absolute filesystem path of the SFTP root directory and of any symlink targets within it. No file contents, credentials, or access to paths outside the root directory are obtainable through this issue alone.
This vulnerability is associated with program files lib/ssh/src/ssh_sftpd.erl.
This issue affects OTP from OTP 17.0 before 29.0.2, 28.5.0.2 and 27.3.4.13 corresponding to ssh from 3.0.1 before 6.0.1, 5.5.2.1 and 5.2.11.8.
Severity
SSVC
Exploitation: none
Automatable: no
Technical Impact: partial
CISA Coordinator (v2.0.3)
CWE
- CWE-200 - Exposure of Sensitive Information to an Unauthorized Actor
Assigner
References
5 references
| URL | Tags |
|---|---|
| https://github.com/erlang/otp/security/advisories… | vendor-advisoryrelated |
| https://cna.erlef.org/cves/CVE-2026-48855.html | related |
| https://osv.dev/vulnerability/EEF-CVE-2026-48855 | related |
| https://www.erlang.org/doc/system/versions.html#o… | x_version-scheme |
| https://github.com/erlang/otp/commit/8f4224a0d267… | patch |
Impacted products
2 products
Credits
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CVE-2026-32147 (GCVE-0-2026-32147)
Vulnerability from nvd – Published: 2026-04-21 12:01 – Updated: 2026-06-10 14:35
VLAI
Title
SFTP chroot bypass via path traversal in SSH_FXP_FSETSTAT
Summary
Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal') vulnerability in Erlang OTP ssh (ssh_sftpd module) allows an authenticated SFTP user to modify file attributes outside the configured chroot directory.
The SFTP daemon (ssh_sftpd) stores the raw, user-supplied path in file handles instead of the chroot-resolved path. When SSH_FXP_FSETSTAT is issued on such a handle, file attributes (permissions, ownership, timestamps) are modified on the real filesystem path, bypassing the root directory boundary entirely.
Any authenticated SFTP user on a server configured with the root option can modify file attributes of files outside the intended chroot boundary. The prerequisite is that a target file must exist on the real filesystem at the same relative path. Note that this vulnerability only allows modification of file attributes; file contents cannot be read or altered through this attack vector.
If the SSH daemon runs as root, this enables direct privilege escalation: an attacker can set the setuid bit on any binary, change ownership of sensitive files, or make system configuration world-writable.
This vulnerability is associated with program files lib/ssh/src/ssh_sftpd.erl and program routines ssh_sftpd:do_open/4 and ssh_sftpd:handle_op/4.
This issue affects OTP from OTP 17.0 until OTP 28.4.3, 27.3.4.11, and 26.2.5.20 corresponding to ssh from 3.01 until 5.5.3, 5.2.11.7, and 5.1.4.15.
Severity
SSVC
Exploitation: none
Automatable: no
Technical Impact: partial
CISA Coordinator (v2.0.3)
CWE
- CWE-22 - Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
Assigner
References
5 references
| URL | Tags |
|---|---|
| https://github.com/erlang/otp/security/advisories… | vendor-advisoryrelated |
| https://cna.erlef.org/cves/CVE-2026-32147.html | related |
| https://osv.dev/vulnerability/EEF-CVE-2026-32147 | related |
| https://www.erlang.org/doc/system/versions.html#o… | x_version-scheme |
| https://github.com/erlang/otp/commit/28c5d5a6c5f8… | patch |
Impacted products
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CVE-2026-23943 (GCVE-0-2026-23943)
Vulnerability from nvd – Published: 2026-03-13 09:11 – Updated: 2026-06-10 14:35
VLAI
Title
Pre-auth SSH DoS via unbounded zlib inflate
Summary
Improper Handling of Highly Compressed Data (Compression Bomb) vulnerability in Erlang OTP ssh (ssh_transport modules) allows Denial of Service via Resource Depletion.
The SSH transport layer advertises legacy zlib compression by default and inflates attacker-controlled payloads pre-authentication without any size limit, enabling reliable memory exhaustion DoS.
Two compression algorithms are affected:
* zlib: Activates immediately after key exchange, enabling unauthenticated attacks
* zlib@openssh.com: Activates post-authentication, enabling authenticated attacks
Each SSH packet can decompress ~255 MB from 256 KB of wire data (1029:1 amplification ratio). Multiple packets can rapidly exhaust available memory, causing OOM kills in memory-constrained environments.
This vulnerability is associated with program files lib/ssh/src/ssh_transport.erl and program routines ssh_transport:decompress/2, ssh_transport:handle_packet_part/4.
This issue affects OTP from OTP 17.0 until OTP 28.4.1, 27.3.4.9 and 26.2.5.18 corresponding to ssh from 3.0.1 until 5.5.1, 5.2.11.6 and 5.1.4.14.
Severity
SSVC
Exploitation: none
Automatable: yes
Technical Impact: partial
CISA Coordinator (v2.0.3)
CWE
- CWE-409 - Improper Handling of Highly Compressed Data (Data Amplification)
Assigner
References
7 references
| URL | Tags |
|---|---|
| https://github.com/erlang/otp/security/advisories… | vendor-advisoryrelated |
| https://cna.erlef.org/cves/CVE-2026-23943.html | related |
| https://osv.dev/vulnerability/EEF-CVE-2026-23943 | related |
| https://www.erlang.org/doc/system/versions.html#o… | x_version-scheme |
| https://github.com/erlang/otp/commit/43a87b949bdf… | patch |
| https://github.com/erlang/otp/commit/93073c3bd338… | patch |
| https://github.com/erlang/otp/commit/0c1c04b191f6… | patch |
Impacted products
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CVE-2026-23942 (GCVE-0-2026-23942)
Vulnerability from nvd – Published: 2026-03-13 09:11 – Updated: 2026-05-27 15:41
VLAI
Title
SFTP root escape via component-agnostic prefix check in ssh_sftpd
Summary
Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal') vulnerability in Erlang OTP (ssh_sftpd module) allows Path Traversal.
This vulnerability is associated with program files lib/ssh/src/ssh_sftpd.erl and program routines ssh_sftpd:is_within_root/2.
The SFTP server uses string prefix matching via lists:prefix/2 rather than proper path component validation when checking if a path is within the configured root directory. This allows authenticated users to access sibling directories that share a common name prefix with the configured root directory. For example, if root is set to /home/user1, paths like /home/user10 or /home/user1_backup would incorrectly be considered within the root.
This issue affects OTP from OTP 17.0 until OTP 28.4.1, OTP 27.3.4.9 and OTP 26.2.5.18, corresponding to ssh from 3.0.1 until 5.5.1, 5.2.11.6 and 5.1.4.14.
Severity
SSVC
Exploitation: none
Automatable: yes
Technical Impact: partial
CISA Coordinator (v2.0.3)
CWE
- CWE-22 - Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
Assigner
References
7 references
| URL | Tags |
|---|---|
| https://github.com/erlang/otp/security/advisories… | vendor-advisoryrelated |
| https://cna.erlef.org/cves/CVE-2026-23942.html | related |
| https://osv.dev/vulnerability/EEF-CVE-2026-23942 | related |
| https://www.erlang.org/doc/system/versions.html#o… | x_version-scheme |
| https://github.com/erlang/otp/commit/27688a824f75… | patch |
| https://github.com/erlang/otp/commit/9e0ac85d3485… | patch |
| https://github.com/erlang/otp/commit/5ed603a1211b… | patch |
Impacted products
Credits
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CVE-2026-48855 (GCVE-0-2026-48855)
Vulnerability from cvelistv5 – Published: 2026-06-10 14:35 – Updated: 2026-06-11 04:45
VLAI
Title
SFTP READLINK Leaks Absolute Backend Filesystem Path When Root Is Configured
Summary
Exposure of Sensitive Information to an Unauthorized Actor vulnerability in Erlang OTP ssh (ssh_sftpd module) allows File Discovery.
The SSH_FXP_READLINK handler in ssh_sftpd sends the raw result of file:read_link/2 to the client without calling chroot_filename/2 to strip the backend root prefix. An authenticated SFTP client can create a symlink inside the chroot pointing to /; ssh_sftpd resolves the target to the absolute backend root and stores it on disk. Reading the symlink back via SSH_FXP_READLINK returns that absolute path, for example /data/sftp, instead of the chrooted value /.
The information disclosed is the absolute filesystem path of the SFTP root directory and of any symlink targets within it. No file contents, credentials, or access to paths outside the root directory are obtainable through this issue alone.
This vulnerability is associated with program files lib/ssh/src/ssh_sftpd.erl.
This issue affects OTP from OTP 17.0 before 29.0.2, 28.5.0.2 and 27.3.4.13 corresponding to ssh from 3.0.1 before 6.0.1, 5.5.2.1 and 5.2.11.8.
Severity
SSVC
Exploitation: none
Automatable: no
Technical Impact: partial
CISA Coordinator (v2.0.3)
CWE
- CWE-200 - Exposure of Sensitive Information to an Unauthorized Actor
Assigner
References
5 references
| URL | Tags |
|---|---|
| https://github.com/erlang/otp/security/advisories… | vendor-advisoryrelated |
| https://cna.erlef.org/cves/CVE-2026-48855.html | related |
| https://osv.dev/vulnerability/EEF-CVE-2026-48855 | related |
| https://www.erlang.org/doc/system/versions.html#o… | x_version-scheme |
| https://github.com/erlang/otp/commit/8f4224a0d267… | patch |
Impacted products
2 products
Credits
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CVE-2026-48859 (GCVE-0-2026-48859)
Vulnerability from cvelistv5 – Published: 2026-06-10 14:35 – Updated: 2026-06-11 04:45
VLAI
Title
SSH server timing side-channel in ssh_auth:check_password/3 allows unauthenticated username enumeration
Summary
Observable Timing Discrepancy vulnerability in Erlang/OTP ssh (ssh_auth, ssh_options modules) allows unauthenticated remote username enumeration via timing side-channel in password authentication.
When the SSH daemon is configured with the user_passwords or password option, ssh_auth:check_password/3 performs a PBKDF2-SHA256 computation with 600,000 iterations (~300ms) for valid usernames, but returns immediately (~0ms) for invalid usernames via the ssh_options:get_password_option/2 path. This timing difference is detectable in a single authentication attempt and allows an unauthenticated attacker to distinguish valid from invalid usernames.
The user_passwords and password options are documented as intended for test purposes; the recommended alternative is pwdfun, which is not affected by this vulnerability.
This vulnerability is associated with program files lib/ssh/src/ssh_auth.erl and lib/ssh/src/ssh_options.erl.
This issue affects OTP from OTP 29.0 before 29.0.2 corresponding to ssh from 6.0 before 6.0.1.
Severity
SSVC
Exploitation: none
Automatable: yes
Technical Impact: partial
CISA Coordinator (v2.0.3)
CWE
- CWE-208 - Observable Timing Discrepancy
Assigner
References
5 references
| URL | Tags |
|---|---|
| https://github.com/erlang/otp/security/advisories… | vendor-advisoryrelated |
| https://cna.erlef.org/cves/CVE-2026-48859.html | related |
| https://osv.dev/vulnerability/EEF-CVE-2026-48859 | related |
| https://www.erlang.org/doc/system/versions.html#o… | x_version-scheme |
| https://github.com/erlang/otp/commit/c342092ef4b3… | patch |
Impacted products
2 products
Credits
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CVE-2026-32147 (GCVE-0-2026-32147)
Vulnerability from cvelistv5 – Published: 2026-04-21 12:01 – Updated: 2026-06-10 14:35
VLAI
Title
SFTP chroot bypass via path traversal in SSH_FXP_FSETSTAT
Summary
Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal') vulnerability in Erlang OTP ssh (ssh_sftpd module) allows an authenticated SFTP user to modify file attributes outside the configured chroot directory.
The SFTP daemon (ssh_sftpd) stores the raw, user-supplied path in file handles instead of the chroot-resolved path. When SSH_FXP_FSETSTAT is issued on such a handle, file attributes (permissions, ownership, timestamps) are modified on the real filesystem path, bypassing the root directory boundary entirely.
Any authenticated SFTP user on a server configured with the root option can modify file attributes of files outside the intended chroot boundary. The prerequisite is that a target file must exist on the real filesystem at the same relative path. Note that this vulnerability only allows modification of file attributes; file contents cannot be read or altered through this attack vector.
If the SSH daemon runs as root, this enables direct privilege escalation: an attacker can set the setuid bit on any binary, change ownership of sensitive files, or make system configuration world-writable.
This vulnerability is associated with program files lib/ssh/src/ssh_sftpd.erl and program routines ssh_sftpd:do_open/4 and ssh_sftpd:handle_op/4.
This issue affects OTP from OTP 17.0 until OTP 28.4.3, 27.3.4.11, and 26.2.5.20 corresponding to ssh from 3.01 until 5.5.3, 5.2.11.7, and 5.1.4.15.
Severity
SSVC
Exploitation: none
Automatable: no
Technical Impact: partial
CISA Coordinator (v2.0.3)
CWE
- CWE-22 - Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
Assigner
References
5 references
| URL | Tags |
|---|---|
| https://github.com/erlang/otp/security/advisories… | vendor-advisoryrelated |
| https://cna.erlef.org/cves/CVE-2026-32147.html | related |
| https://osv.dev/vulnerability/EEF-CVE-2026-32147 | related |
| https://www.erlang.org/doc/system/versions.html#o… | x_version-scheme |
| https://github.com/erlang/otp/commit/28c5d5a6c5f8… | patch |
Impacted products
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CVE-2026-23943 (GCVE-0-2026-23943)
Vulnerability from cvelistv5 – Published: 2026-03-13 09:11 – Updated: 2026-06-10 14:35
VLAI
Title
Pre-auth SSH DoS via unbounded zlib inflate
Summary
Improper Handling of Highly Compressed Data (Compression Bomb) vulnerability in Erlang OTP ssh (ssh_transport modules) allows Denial of Service via Resource Depletion.
The SSH transport layer advertises legacy zlib compression by default and inflates attacker-controlled payloads pre-authentication without any size limit, enabling reliable memory exhaustion DoS.
Two compression algorithms are affected:
* zlib: Activates immediately after key exchange, enabling unauthenticated attacks
* zlib@openssh.com: Activates post-authentication, enabling authenticated attacks
Each SSH packet can decompress ~255 MB from 256 KB of wire data (1029:1 amplification ratio). Multiple packets can rapidly exhaust available memory, causing OOM kills in memory-constrained environments.
This vulnerability is associated with program files lib/ssh/src/ssh_transport.erl and program routines ssh_transport:decompress/2, ssh_transport:handle_packet_part/4.
This issue affects OTP from OTP 17.0 until OTP 28.4.1, 27.3.4.9 and 26.2.5.18 corresponding to ssh from 3.0.1 until 5.5.1, 5.2.11.6 and 5.1.4.14.
Severity
SSVC
Exploitation: none
Automatable: yes
Technical Impact: partial
CISA Coordinator (v2.0.3)
CWE
- CWE-409 - Improper Handling of Highly Compressed Data (Data Amplification)
Assigner
References
7 references
| URL | Tags |
|---|---|
| https://github.com/erlang/otp/security/advisories… | vendor-advisoryrelated |
| https://cna.erlef.org/cves/CVE-2026-23943.html | related |
| https://osv.dev/vulnerability/EEF-CVE-2026-23943 | related |
| https://www.erlang.org/doc/system/versions.html#o… | x_version-scheme |
| https://github.com/erlang/otp/commit/43a87b949bdf… | patch |
| https://github.com/erlang/otp/commit/93073c3bd338… | patch |
| https://github.com/erlang/otp/commit/0c1c04b191f6… | patch |
Impacted products
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CVE-2026-23942 (GCVE-0-2026-23942)
Vulnerability from cvelistv5 – Published: 2026-03-13 09:11 – Updated: 2026-05-27 15:41
VLAI
Title
SFTP root escape via component-agnostic prefix check in ssh_sftpd
Summary
Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal') vulnerability in Erlang OTP (ssh_sftpd module) allows Path Traversal.
This vulnerability is associated with program files lib/ssh/src/ssh_sftpd.erl and program routines ssh_sftpd:is_within_root/2.
The SFTP server uses string prefix matching via lists:prefix/2 rather than proper path component validation when checking if a path is within the configured root directory. This allows authenticated users to access sibling directories that share a common name prefix with the configured root directory. For example, if root is set to /home/user1, paths like /home/user10 or /home/user1_backup would incorrectly be considered within the root.
This issue affects OTP from OTP 17.0 until OTP 28.4.1, OTP 27.3.4.9 and OTP 26.2.5.18, corresponding to ssh from 3.0.1 until 5.5.1, 5.2.11.6 and 5.1.4.14.
Severity
SSVC
Exploitation: none
Automatable: yes
Technical Impact: partial
CISA Coordinator (v2.0.3)
CWE
- CWE-22 - Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
Assigner
References
7 references
| URL | Tags |
|---|---|
| https://github.com/erlang/otp/security/advisories… | vendor-advisoryrelated |
| https://cna.erlef.org/cves/CVE-2026-23942.html | related |
| https://osv.dev/vulnerability/EEF-CVE-2026-23942 | related |
| https://www.erlang.org/doc/system/versions.html#o… | x_version-scheme |
| https://github.com/erlang/otp/commit/27688a824f75… | patch |
| https://github.com/erlang/otp/commit/9e0ac85d3485… | patch |
| https://github.com/erlang/otp/commit/5ed603a1211b… | patch |
Impacted products
Credits
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"value": "\u003cul\u003e\u003cli\u003eUse OS-level chroot to run the Erlang VM/SFTP server process in an isolated filesystem environment.\u003c/li\u003e\u003cli\u003eEnsure that no sensitive or precious data is readable or writable by the OS user running the Erlang VM.\u003c/li\u003e\u003cli\u003eEnsure that the SFTP server port is not reachable from untrusted machines.\u003c/li\u003e\u003cli\u003eUse directory naming conventions that avoid common prefixes (e.g., \u003ctt\u003e/home/users/alice/\u003c/tt\u003e instead of \u003ctt\u003e/home/user1/\u003c/tt\u003e).\u003c/li\u003e\u003c/ul\u003e"
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"value": "* Use OS-level chroot to run the Erlang VM/SFTP server process in an isolated filesystem environment.\n* Ensure that no sensitive or precious data is readable or writable by the OS user running the Erlang VM.\n* Ensure that the SFTP server port is not reachable from untrusted machines.\n* Use directory naming conventions that avoid common prefixes (e.g., /home/users/alice/ instead of /home/user1/)."
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"cveMetadata": {
"assignerOrgId": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db",
"assignerShortName": "EEF",
"cveId": "CVE-2026-23942",
"datePublished": "2026-03-13T09:11:56.424Z",
"dateReserved": "2026-01-19T14:23:14.343Z",
"dateUpdated": "2026-05-27T15:41:40.808Z",
"state": "PUBLISHED"
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