Cyber Resilience

CVE-2026-48855

Info Disclosure in Erlang\/Otp 17.0 – 27.3.4.13

Published
10 June 2026
Modified
24 July 2026
Patch / advisory
CVSS Score v4 2.3
Click a component to see what it means
Raw vectorCVSS: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
EPSS Score 0.0028 20th percentile
Risk Priority 15 floored blend · peak EPSS

Summary

CVE-2026-48855 is a low-severity Exposure of Sensitive Information to an Unauthorized Actor (CWE-200) vulnerability in Erlang Erlang\/Otp. Its CVSS base score is 2.3 (Low).

Operationally, exploitation aligns with the MITRE ATT&CK technique System Information Discovery (T1082); ranked at the 20th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified map to AC-4 (Information Flow Enforcement) and SI-15 (Information Output Filtering) — see the control section below for these in your framework.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability Data

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…

more

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 29.0.2, OTP 28.5.0.2 and OTP 27.3.4.13, corresponding to ssh from 3.0.1 before 6.0.1, 5.5.2.1 and 5.2.11.8.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

T1082 System Information Discovery Discovery
An adversary may attempt to get detailed information about the operating system and hardware, including version, patches, hotfixes, service packs, and architecture.
Why these techniques?

Vulnerability enables disclosure of absolute filesystem paths to an authenticated client, directly facilitating System Information Discovery (T1082).

Confidence: MEDIUM · MITRE ATT&CK Enterprise v19.0

CVEs Like This One

CVE-2026-54886Same product: Erlang Erlang\/Otp
CVE-2026-53422Same product: Erlang Erlang\/Otp
CVE-2026-32147Same product: Erlang Erlang\/Otp
CVE-2026-23943Same product: Erlang Erlang\/Otp
CVE-2026-23942Same product: Erlang Erlang\/Otp
CVE-2026-48859Same product: Erlang Erlang\/Otp
CVE-2026-42790Same product: Erlang Erlang\/Otp
CVE-2026-42791Same product: Erlang Erlang\/Otp
CVE-2026-42789Same product: Erlang Erlang\/Otp
CVE-2026-28810Same product: Erlang Erlang\/Otp

Affected Assets

erlang
erlang\/otp
17.0 — 27.3.4.13 · 28.0 — 28.5.0.2 · 29.0 — 29.0.2
erlang
erlang\/ssh
3.0.1 — 5.2.11.8 · 5.5 — 5.5.2.1 · 6.0 — 6.0.1

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)
  • SI-15 Information Output Filtering
  • AC-4 Information Flow Enforcement
  • AC-3 Access Enforcement
Detect
Catch it (NIST detect / respond)

Harden
Shrink the surface (DISA STIG)
  • 7 hardening rules · 6 OS baselines
Validate
Prove the fix (OWASP ASVS)
  • V10.4.9
  • V11.7.1
  • V14.1.2
  • V14.2.4

Mitigating Controls (NIST 800-53 r5) AI

prevent

Directly requires filtering of sensitive internal filesystem paths from SFTP protocol responses such as SSH_FXP_READLINK before they are returned to the client.

prevent

Enforces information flow rules that prohibit disclosure of backend absolute paths (e.g., /data/sftp) through the chrooted SFTP interface.

prevent

Access enforcement can be configured to deny symlink creation or READLINK operations that would otherwise leak the un-sanitized root directory path.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.AA-05 mostly match
prevents

PR.AA-05 directly enforces least-privilege authorization that blocks most unauthorized disclosures, yet CWE-200 also arises from logging, error messages, and side-channel paths that access controls alone do not address.

PR.DS-10 mostly match
prevents

PR.DS-10 mostly prevents CWE-200 by directly eliminating unauthorized access to sensitive data-in-use, yet only partially addresses the weakness because CWE-200 spans many other exposure vectors outside runtime protection.

PR.IR-01 mostly match
prevents

PR.IR-01's segmentation/zero-trust controls largely eliminate network-level unauthorized access paths that enable exposure, yet CWE-200 spans many additional vectors (API responses, logs, app logic) that network controls alone cannot close.

PR.PS-06 mostly match
prevents

Secure SDLC practices catch most exposure flaws via design, testing and release controls, yet CWE-200 spans runtime/config issues a single development outcome cannot fully close.

PR.AA-01 partial match
prevents

PR.AA-01 supplies proper credential lifecycle controls that reduce unauthorized access paths, yet leaves many other exposure vectors (error messages, logging, side channels, etc.) unaddressed.

PR.AA-03 partial match
prevents

Authentication verifies actor identity and is a prerequisite for access decisions, yet addresses only one facet of the broad set of exposure vectors in CWE-200.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

prevents

Restricting anonymous or unknown access and encrypting high-value information limits the exposure of sensitive data that would otherwise be obtainable by unauthorized actors.

prevents

Suppressing system details, error specifics, and previous log-on information until successful authentication reduces the information an unauthenticated attacker can gather.

prevents

By requiring owners to assign sensitivity labels and corresponding handling rules, the control ensures that information is not left unmarked and therefore reduces the chance that sensitive data will be exposed to unauthorized actors.

prevents

Requiring encryption, access controls, and recipient authentication for transfers directly reduces the chance that sensitive data reaches an unauthorized observer.

prevents

Secure delivery, protected storage, and confidentiality of allocation records limit exposure of authentication material to unauthorized observers.

prevents

Requiring defined procedures, assigned roles, and technical/organizational measures for handling PII reduces the chance that sensitive personal data will be exposed to unauthorized actors through inadequate handling or missing safeguards.

References