SFTP READLINK Leaks Absolute Backend Filesystem Path When Root Is Configured
Noroxi assessment
Priority: Monitor (action score 9/100)
- The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
- Probability of exploitation in the next 30 days: 0.29% (FIRST EPSS).
- Anyone who can reach it over the internet can trigger it. A low-privileged account is enough. No user action is required. No special conditions are required; it is repeatable.
- Fixed version: Erlang OTP 27.3.4.13, 28.5.0.2, 29.0.2; azl3 erlang 26.2.5.20-1 on Azure Linux 3.0 26.2.5.21-2.
Low priority for now. Upgrade to Erlang OTP 27.3.4.13, 28.5.0.2, 29.0.2; azl3 erlang 26.2.5.20-1 on Azure Linux 3.0 26.2.5.21-2 or later.
Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it
Primary sources: NVD · CVE.org · FIRST EPSS
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 OTP 27.3.4.13, OTP 28.5.0.2, and OTP 29.0.2, corresponding to ssh from 3.0.1 before 5.2.11.8, 5.5.2.1, and 6.0.1. Whether OTP before OTP 17.0, corresponding to ssh before 3.0.1, is affected is unknown.
- Published
- Jun 10, 2026
- Updated
- Sep 24, 2026
- EPSS
- 0.2% · 21th percentile
- CWE
- CWE-200
Report tools
Action score
9
Monitor
Low priority for now.
- CVSS
- 9 / 40 · 2.3 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 0 / 30 · 0.2%
CISA SSVC decision
- Exploitation
- none
- Automatable
- no
- Technical impact
- partial
Vulnrichment: CISA's decision-tree inputs.
CNA vs NVD score
- NVD
- —
- CNA · EEF
- 2.3
- NVD has not scored this yet; the score shown is the CNA’s.
CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N
The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.
Get told when this record changes
- Not in KEV: no record of exploitation in the wild
- No public exploit code on record
- A fix has been released
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Noroxi analysis
What does it mean in your environment?
The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.
We use this product, ask for helpAffected systems
Is your version affected?
Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.
| Vendor | Product | CPE |
|---|---|---|
| erlang | erlang\/otp | cpe:2.3:a:erlang:erlang\/otp |
| erlang | erlang\/ssh | cpe:2.3:a:erlang:erlang\/ssh |
Affected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- erlang erlang/otp17.0 and later · before 27.3.4.13
- erlang erlang/otp28.0 and later · before 28.5.0.2
- erlang erlang/otp29.0 and later · before 29.0.2
- erlang erlang/ssh3.0.1 and later · before 5.2.11.8
- erlang erlang/ssh5.5 and later · before 5.5.2.1
- erlang erlang/ssh6.0 and later · before 6.0.1
Versions reported by the vendor
Affected version ranges reported by the assigning authority (EEF). Independent of NVD's CPE analysis and usually ahead of it.
Erlang OTP
- 17.0 and lateraffected · otpfixed in 27.3.4.13, 28.5.0.2, 29.0.2
- 3.0.1 and lateraffected · otpfixed in 5.2.11.8, 5.5.2.1, 6.0.1
- 08225797f7ef943d0c82a1d9dd6650d94ca2580d and later · before 8f4224a0d2676b0653d2c71a889a956e8c2c62d6affected · git
- 8f4224a0d2676b0653d2c71a889a956e8c2c62d6 and laternot affected · git
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| Debian:12 | erlang | from 0 | — |
| Debian:13 | erlang | before 1:27.3.4.1+dfsg-1+deb13u3 | 1:27.3.4.1+dfsg-1+deb13u3 |
| Debian:14 | erlang | before 1:29.0.2+dfsg-1 | 1:29.0.2+dfsg-1 |
| openSUSE:Tumbleweed | erlang | before 28.5.0.4-1.1 | 28.5.0.4-1.1 |
| openSUSE:Tumbleweed | erlang27 | before 27.1.3-3.1 | 27.1.3-3.1 |
| Red Hat:hummingbird:1 | erlang27 | before 0:27.3.4.17-1.hum1 | 0:27.3.4.17-1.hum1 |
| Red Hat:hummingbird:1 | erlang27-asn1 | before 0:27.3.4.17-1.hum1 | 0:27.3.4.17-1.hum1 |
| Red Hat:hummingbird:1 | erlang27-common_test | before 0:27.3.4.17-1.hum1 | 0:27.3.4.17-1.hum1 |
| Red Hat:hummingbird:1 | erlang27-compiler | before 0:27.3.4.17-1.hum1 | 0:27.3.4.17-1.hum1 |
| Red Hat:hummingbird:1 | erlang27-crypto | before 0:27.3.4.17-1.hum1 | 0:27.3.4.17-1.hum1 |
| Red Hat:hummingbird:1 | erlang27-debugger | before 0:27.3.4.17-1.hum1 | 0:27.3.4.17-1.hum1 |
| Red Hat:hummingbird:1 | erlang27-dialyzer | before 0:27.3.4.17-1.hum1 | 0:27.3.4.17-1.hum1 |
| Red Hat:hummingbird:1 | erlang27-diameter | before 0:27.3.4.17-1.hum1 | 0:27.3.4.17-1.hum1 |
| Red Hat:hummingbird:1 | erlang27-edoc | before 0:27.3.4.17-1.hum1 | 0:27.3.4.17-1.hum1 |
| Red Hat:hummingbird:1 | erlang27-eldap | before 0:27.3.4.17-1.hum1 | 0:27.3.4.17-1.hum1 |
| Red Hat:hummingbird:1 | erlang27-erl_interface | before 0:27.3.4.17-1.hum1 | 0:27.3.4.17-1.hum1 |
| Red Hat:hummingbird:1 | erlang27-erts | before 0:27.3.4.17-1.hum1 | 0:27.3.4.17-1.hum1 |
| Red Hat:hummingbird:1 | erlang27-et | before 0:27.3.4.17-1.hum1 | 0:27.3.4.17-1.hum1 |
| Red Hat:hummingbird:1 | erlang27-eunit | before 0:27.3.4.17-1.hum1 | 0:27.3.4.17-1.hum1 |
| Red Hat:hummingbird:1 | erlang27-examples | before 0:27.3.4.17-1.hum1 | 0:27.3.4.17-1.hum1 |
| Red Hat:hummingbird:1 | erlang27-ftp | before 0:27.3.4.17-1.hum1 | 0:27.3.4.17-1.hum1 |
| Red Hat:hummingbird:1 | erlang27-gdb-tools | before 0:27.3.4.17-1.hum1 | 0:27.3.4.17-1.hum1 |
| Red Hat:hummingbird:1 | erlang27-inets | before 0:27.3.4.17-1.hum1 | 0:27.3.4.17-1.hum1 |
| Red Hat:hummingbird:1 | erlang27-jinterface | before 0:27.3.4.17-1.hum1 | 0:27.3.4.17-1.hum1 |
+22
Same product
erlang: all recordsOther highest-scoring records for the same primary product.
- CVE-2025-32433Erlang/OTP SSH Vulnerable to Pre-Authentication RCEKEV100Now
- CVE-2017-1000385The Erlang otp TLS server answers with different TLS alerts to different error types in the RSA PKCS #1 1.5 padding.60This week
- CVE-2022-37026In Erlang/OTP before 23.3.4.15, 24.x before 24.3.4.2, and 25.x before 25.0.2, there is a Client Authentication Bypass in certain client-cert39Monitor
Published before and after this one in the same product
- ← EarlierCVE-2026-42791May 27, 2026 · OCSP responder certificate validity period not checked in public_key25Monitor
- ← EarlierCVE-2026-42790May 27, 2026 · nameConstraints DNS bypass via subject CommonName fallback in public_key hostname verification30Monitor
- Later →CVE-2026-48859Jun 10, 2026 · SSH server timing side-channel in ssh_auth:check_password/3 allows unauthenticated username enumeration25Monitor
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
| Product / package | Fixed version | Source |
|---|---|---|
| Erlang OTP | 27.3.4.13 | Vendor (CNA) |
| Erlang OTP | 28.5.0.2 | Vendor (CNA) |
| Erlang OTP | 29.0.2 | Vendor (CNA) |
| Erlang OTP | 5.2.11.8 | Vendor (CNA) |
| Erlang OTP | 5.5.2.1 | Vendor (CNA) |
| Erlang OTP | 6.0.1 | Vendor (CNA) |
| Erlang OTP | 8f4224a0d2676b0653d2c71a889a956e8c2c62d6 | Vendor (CNA) |
| azl3 erlang 26.2.5.20-1 on Azure Linux 3.0 | 26.2.5.21-2 · CBL-Mariner Releases | Microsoft (MSRC) |
| debian:erlang | 1:27.3.4.1+dfsg-1+deb13u3 · Debian:13 | Package registry (OSV) |
| opensuse:erlang | 28.5.0.4-1.1 · openSUSE:Tumbleweed | Package registry (OSV) |
| opensuse:erlang27 | 27.1.3-3.1 · openSUSE:Tumbleweed | Package registry (OSV) |
| red hat:erlang27 | 0:27.3.4.17-1.hum1 · Red Hat:hummingbird:1 | Package registry (OSV) |
| red hat:erlang27-asn1 | 0:27.3.4.17-1.hum1 · Red Hat:hummingbird:1 | Package registry (OSV) |
| red hat:erlang27-common_test | 0:27.3.4.17-1.hum1 · Red Hat:hummingbird:1 | Package registry (OSV) |
| red hat:erlang27-compiler | 0:27.3.4.17-1.hum1 · Red Hat:hummingbird:1 | Package registry (OSV) |
| red hat:erlang27-crypto | 0:27.3.4.17-1.hum1 · Red Hat:hummingbird:1 | Package registry (OSV) |
| red hat:erlang27-debugger | 0:27.3.4.17-1.hum1 · Red Hat:hummingbird:1 | Package registry (OSV) |
| red hat:erlang27-dialyzer | 0:27.3.4.17-1.hum1 · Red Hat:hummingbird:1 | Package registry (OSV) |
| red hat:erlang27-diameter | 0:27.3.4.17-1.hum1 · Red Hat:hummingbird:1 | Package registry (OSV) |
| red hat:erlang27-edoc | 0:27.3.4.17-1.hum1 · Red Hat:hummingbird:1 | Package registry (OSV) |
| red hat:erlang27-eldap | 0:27.3.4.17-1.hum1 · Red Hat:hummingbird:1 | Package registry (OSV) |
| red hat:erlang27-erl_interface | 0:27.3.4.17-1.hum1 · Red Hat:hummingbird:1 | Package registry (OSV) |
| red hat:erlang27-erts | 0:27.3.4.17-1.hum1 · Red Hat:hummingbird:1 | Package registry (OSV) |
| suse:erlang | 23.3.4.19-150300.3.39.1 · SUSE:Linux Enterprise Module for Server Applications 15 SP7 | Package registry (OSV) |
| suse:erlang26 | 26.2.1-150300.7.28.1 · SUSE:Linux Enterprise Module for Server Applications 15 SP7 | Package registry (OSV) |
Exploit status
No known public exploit
No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.
Research context
For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.
Timeline
From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.
No dated events beyond publication.
FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).
Patch and commit links
Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.
Credits
All researchersFinders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.
- Jakub Witczakremediation reviewer
- Jonatan Männchen / EEFfinder
- Michał Wąsowskiremediation developer
Variant candidates
Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.
No nightly-computed relations.
Chain candidates
An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.
—
Bug bounty scope
No known public program.
Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).
Technical details
Attack conditions
- Anyone who can reach it over the internet can trigger it.
- A low-privileged account is enough.
- No user action is required.
- No special conditions are required; it is repeatable.
If successful
- Confidentiality
- Integrity
- Availability
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- Low
- User interaction
- None
- Scope
- X
Weakness class (CWE)
CWE-200 · Exposure of Sensitive Information to an Unauthorized ActorCVSS vector
CVSS:4.0/AV:N/AC:L/AT:P/PR:L/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
nvd-secondary
Root cause
The extension requests broader permissions than its function needs and sends the data it collects out for purposes beyond its stated function.
The bug in code
The whole CWE-200 classA representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.
Vulnerable
{ "permissions": ["tabs", "<all_urls>"], "background": { "service_worker": "analytics.js" }}Fixed
{ "permissions": ["activeTab"], "host_permissions": ["https://yildiz.example/*"]}Attack context
MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.
Attack patterns (CAPEC)
- ExcavationCAPEC-116likelihood: High · Medium
- Subverting Environment Variable ValuesCAPEC-13likelihood: High · Very High
- FootprintingCAPEC-169likelihood: High · Very Low
- Exploiting Trust in ClientCAPEC-22likelihood: High · High
- FingerprintingCAPEC-224likelihood: High · Very Low
- ICMP Echo Request PingCAPEC-285likelihood: Medium · Low
- TCP SYN ScanCAPEC-287Low
- Enumerate Mail Exchange (MX) RecordsCAPEC-290Low
ATT&CK techniques
- System Service DiscoveryT1007
- System Network Configuration DiscoveryT1016
- Remote System DiscoveryT1018
- System Owner/User DiscoveryT1033
- Masquerading: Match Legitimate Name or LocationT1036.005
- Network Service ScanningT1046
- System Network Connections DiscoveryT1049
- Process DiscoveryT1057
- Permission Groups DiscoveryT1069
- System Information DiscoveryT1082
- File and Directory DiscoveryT1083
- Account DiscoveryT1087
- Multi-Factor Authentication InterceptionT1111
- Peripheral Device DiscoveryT1120
- System Time DiscoveryT1124
- Access Token Manipulation:Token Impersonation/TheftT1134.001
Change log
- Fix✗ → ✓
For records you follow, these changes also arrive as notifications. →
References
Show all references (5 more)Show less
Vendor advisories and official records. Exploit/PoC links are deliberately left out.