Cyber Resilience

CVE-2026-27976

Zed ≤ 0.224.4

Public PoC
Published
26 February 2026
Modified
05 March 2026
Patch / advisory
CVSS Score v3.1 8.8
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:H
EPSS Score 0.0049 40th percentile
Risk Priority 64 floored blend · peak EPSS

Summary

CVE-2026-27976 is a high-severity UNIX Symbolic Link (Symlink) Following (CWE-61) vulnerability in Zed Zed. Its CVSS base score is 8.8 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Path Interception (T1034); ranked at the 40th 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-3 (Access Enforcement) and AC-4 (Information Flow 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-2026-27976 is a symlink following vulnerability (CWE-61) in the Zed code editor's extension installer, affecting versions prior to 0.224.4. The issue stems from the tar extractor (`async_tar::Archive::unpack`) creating symlinks from tar/gzip archives without validation, combined with the path guard (`writeable_path_from_extension`) performing only lexical prefix checks without resolving symlinks. This allows malicious archives downloaded during extension installation to bypass sandboxing restrictions.

An attacker can exploit this remotely over the network with no privileges by crafting a tar archive for a malicious extension. The archive first creates a symlink within the extension workdir pointing to an arbitrary host path (e.g., `escape -> /`), followed by files written through that symlink, enabling arbitrary file writes outside the sandbox and potential code execution on the host. Exploitation requires user interaction to install the extension, as indicated by the CVSS v3.1 score of 8.8 (AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H).

Zed version 0.224.4 patches the vulnerability by addressing the symlink handling in the extractor and path validation. Additional details are available in the GitHub Security Advisory at https://github.com/zed-industries/zed/security/advisories/GHSA-59p4-3mhm-qm3r.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability Data

Zed, a code editor, has an extension installer allows tar/gzip downloads. Prior to version 0.224.4, the tar extractor (`async_tar::Archive::unpack`) creates symlinks from the archive without validation, and the path guard (`writeable_path_from_extension`) only performs lexical prefix checks without resolving symlinks. An…

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attacker can ship a tar that first creates a symlink inside the extension workdir pointing outside (e.g., `escape -> /`), then writes files through the symlink, causing writes to arbitrary host paths. This escapes the extension sandbox and enables code execution. Version 0.224.4 patches the issue.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise Techniques

T1034 Path Interception Persistence
**This technique has been deprecated.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2026-44461Same product: Zed Zed
CVE-2026-25805Same product: Zed Zed
CVE-2026-44463Same product: Zed Zed
CVE-2026-44466Same product: Zed Zed
CVE-2026-44465Same product: Zed Zed
CVE-2026-27800Same product: Zed Zed
CVE-2026-27967Same product: Zed Zed
CVE-2025-68432Same product: Zed Zed
CVE-2026-44462Same product: Zed Zed
CVE-2025-68433Same product: Zed Zed

Affected Assets

zed
zed
≤ 0.224.4

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

Detect
Catch it (NIST detect / respond)

Harden
Shrink the surface (DISA STIG)
  • 2 hardening rules · 2 OS baselines
Validate
Prove the fix (OWASP ASVS)
  • V5.2.5

Mitigating Controls (NIST 800-53 r5) AI

Access enforcement must resolve the actual target of any file reference and apply authorizations to it, directly stopping symlink traversal to unauthorized objects.

Information-flow enforcement on file operations must follow the resolved target rather than the link name, blocking unauthorized data movement via symlinks.

Least-privilege restrictions on the directories that may contain links or targets reduce the set of files an attacker can reach even if a symlink is followed.

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.PS-06 mostly match
prevents

Secure SDLC practices directly prevent introduction of symlink-following flaws in file-handling code.

ID.RA-01 partial match
prevents

Vulnerability identification can discover existing symlink issues but does not prevent or remediate them in code.

PR.AA-05 partial match
prevents

Least-privilege access policies can limit damage from symlink attacks but do not address the coding flaw itself.

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 symlink-following vulnerabilities before deployment, covering most of the weakness.

prevents

Secure-architecture principles require safe file-handling and canonicalization, directly addressing symlink attacks.

prevents

Secure-coding standards mandate explicit symlink checks and safe open patterns, fully mitigating CWE-61.

mitigates

Access-control rules can restrict which files a process may open, reducing symlink-following risk but not eliminating the underlying path-resolution flaw.

none

Configuration management can enforce safe file-permission baselines that limit symlink abuse, but does not address the code flaw itself.

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 (1 rule)
  • V-248577 OL 8 must enable kernel parameters to enforce Discretionary Access Control (DAC) on symlinks. prevents CWE-61

References