Cyber Resilience

CVE-2026-34581

Auth Bypass in Goshs 1.1.0 – 2.0.0

Public PoCAuth Bypass
Published
02 April 2026
Modified
24 July 2026
Patch / advisory
CVSS Score v3.1 8.1
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N
EPSS Score 0.0039 32th percentile
Risk Priority 59 floored blend · peak EPSS

Summary

CVE-2026-34581 is a high-severity Authentication Bypass Using an Alternate Path or Channel (CWE-288) vulnerability in Goshs Goshs. Its CVSS base score is 8.1 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 32th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

The strongest mitigations our analysis identified map to AC-25 (Reference Monitor) and AC-3 (Access Enforcement) — see the control section below for these in your framework.

Deeper analysis AI-assisted summary

Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.

CVE-2026-34581 is a vulnerability in goshs, a SimpleHTTPServer written in Go. It affects versions from 1.1.0 up to but not including 2.0.0-beta.2. The flaw enables bypassing the Share Token mechanism, which is intended to restrict downloads to selected files only, thereby granting access to all goshs functionalities, including code execution. The vulnerability carries a CVSS v3.1 base score of 8.1 (AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N) and maps to CWE-288 (Authentication Bypass Using an Alternate Path or Channel).

A remote attacker requires no privileges and can exploit this over the network with low complexity, though user interaction is needed. By tricking a user into engaging with a malicious request or link involving the Share Token, the attacker can bypass restrictions to access full server capabilities, achieving high-impact confidentiality and integrity violations such as arbitrary code execution on the affected system.

The vulnerability has been patched in goshs version 2.0.0-beta.2. Mitigation involves updating to this version or later. Key resources include the patching commit at https://github.com/patrickhener/goshs/commit/6fb224ed15c2ccc0c61a5ebe22f2401eb06e9216, the release announcement at https://github.com/patrickhener/goshs/releases/tag/v2.0.0-beta.2, and the GitHub security advisory at https://github.com/patrickhener/goshs/security/advisories/GHSA-jgfx-74g2-9r6g.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability Data

goshs is a SimpleHTTPServer written in Go. From version 1.1.0 to before version 2.0.0-beta.2, when using the Share Token it is possible to bypass the limited selected file download with all the gosh functionalities, including code exec. This issue has…

more

been patched in version 2.0.0-beta.2.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise Techniques

T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
T1211 Exploitation for Stealth Stealth
Adversaries may exploit vulnerabilities to evade detection by hiding activity, suppressing logging, or operating within trusted or unmonitored components.
T1542.002 Component Firmware Stealth
Adversaries may modify component firmware to persist on systems.
T1556 Modify Authentication Process Defense Impairment
Adversaries may modify authentication mechanisms and processes to access user credentials or enable otherwise unwarranted access to accounts.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2026-40189Same product: Goshs Goshs
CVE-2026-42091Same product: Goshs Goshs
CVE-2026-35393Same product: Goshs Goshs
CVE-2026-35392Same product: Goshs Goshs
CVE-2026-40876Same product: Goshs Goshs
CVE-2026-35471Same product: Goshs Goshs
CVE-2026-40883Same product: Goshs Goshs
CVE-2026-40884Same product: Goshs Goshs
CVE-2026-40885Same product: Goshs Goshs
CVE-2026-40903Same product: Goshs Goshs

Affected Assets

goshs
goshs
2.0.0 · 1.1.0 — 2.0.0

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

Detect
Catch it (NIST detect / respond)

Harden
Shrink the surface (DISA STIG)
  • 7 hardening rules · 3 OS baselines
Validate
Prove the fix (OWASP ASVS)
  • V6.4.3
  • V6.6.1
  • V12.1.3

Mitigating Controls (NIST 800-53 r5) AI

Requires a tamperproof, always-invoked reference monitor that structurally blocks bypass via any alternate path.

Enforces authorization checks on every logical access path, eliminating unauthenticated alternate channels.

Mandates unique identification and authentication for all organizational users, covering the primary authentication requirement.

Controls all external and key internal interfaces, reducing the chance of unauthenticated alternate channels.

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-03 full match
prevents

Requiring authentication on every channel and path directly eliminates alternate-path bypasses.

PR.AA-05 mostly match
prevents

Enforcing authorizations and least privilege across all access vectors prevents unauthenticated alternate paths.

PR.IR-01 mostly match
prevents

Protecting networks and environments from unauthorized logical access blocks bypass via undocumented channels.

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.

finds

Security testing can detect alternate-path bypasses but does not prevent them in production.

degrades

Secure authentication control directly mitigates bypass by requiring strong, consistent authentication on all paths.

prevents

Access control policy directly addresses alternate authentication paths by requiring all channels to enforce authentication.

degrades

Authentication information management ensures credentials and mechanisms are consistently applied across all access paths.

prevents

Access rights provisioning and review prevent bypass via unmonitored or alternate channels.

prevents

Privileged access rights control reduces risk of bypass through elevated or alternate paths.

Hardening callouts derived

Configuration rules from DISA STIG baselines that bear on weaknesses of the type cited by this CVE. Each rule is shown with the relationship its mapping actually records, against the CWE it was authored against. Derived via CVE→CWE over `controls_xwalks` (authoritative rows only; rows rated `none` are excluded).

Oracle Linux 8 (2 rules)
  • V-248598 There must be no ".shosts" files on the OL 8 operating system. prevents CWE-288
  • V-248827 OL 8 must not have the rsh-server package installed. prevents CWE-288
Oracle Linux 9 (2 rules)
  • V-271757 OL 9 file systems must not contain shosts.equiv files. prevents CWE-288
  • V-271758 OL 9 file systems must not contain .shosts files. prevents CWE-288
RHEL 7 (3 rules)
  • V-204440 Red Hat Enterprise Linux operating systems version 7.2 or newer using Unified Extensible Firmware Interface (UEFI) must require authentication upon booting into single-user and maintenance modes. prevents CWE-288
  • V-204442 The Red Hat Enterprise Linux operating system must not have the rsh-server package installed. prevents CWE-288
  • V-204424 The Red Hat Enterprise Linux operating system must not allow accounts configured with blank or null passwords. prevents CWE-288

References