CVE-2026-27606 | Rollup 4 has Arbitrary File Write via Path Traversal

Exp

Rollup is a module bundler for JavaScript. Versions prior to 2.80.0, 3.30.0, and 4.59.0 of the Rollup module bundler (specifically v4.x and present in current source) is vulnerable to an Arbitrary File Write via Path Traversal. Insecure file name sanitization in the core engine allows an attacker to control output filenames (e.g., via CLI named inputs, manual chunk aliases, or malicious plugins) and use traversal sequences (`../`) to overwrite files anywhere on the host filesystem that the build process has permissions for. This can lead to persistent Remote Code Execution (RCE) by overwriting critical system or user configuration files. Versions 2.80.0, 3.30.0, and 4.59.0 contain a patch for the issue.

Published: 2026-02-25 Last update: 2026-02-25 Assigner: [email protected] Source: [email protected]
NVD Status：Analyzed，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2026-27606 is rated High Exploit Risk (73.4/100): CVSS High severity, with medium exploitation likelihood (EPSS 1.20%). 1 public exploit reference(s) are indexed (Exploit-DB). Public exploits are available—assess exposure, apply mitigations, and prioritize patching.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Public exploit references (Exploit-DB) for CVE-2026-27606

EDB-ID Source Kind Published Link
— nvd_ref exploit_tag Exploit-DB ↗

Exploit prediction scoring system (EPSS) score for CVE-2026-27606

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 0.38% 1.20% +0.81%
2 2026-04-08 0.26% 0.38% +0.12%
3 2026-03-21 — 0.26% —

Full EPSS history (6 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-27606

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
8.8 4.0 HIGH
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:P/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 Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network.
Attack complexity (AC:L)
Exploitation conditions are straightforward and stable.
Attack requirements (AT:N)
No additional preconditions are required beyond normal reachability.
Privileges required (PR:N)
No privileges are required.
User interaction (UI:N)
No user interaction is required.
Vulnerable system confidentiality impact (VC:H)
High confidentiality impact on the vulnerable system.
Vulnerable system integrity impact (VI:H)
High integrity impact on the vulnerable system.
Vulnerable system availability impact (VA:N)
No availability impact on the vulnerable system.
Subsequent system confidentiality impact (SC:N)
No confidentiality impact on subsequent systems.
Subsequent system integrity impact (SI:N)
No integrity impact on subsequent systems.
Subsequent system availability impact (SA:N)
No availability impact on subsequent systems.
Exploit maturity (threat) (E:P)
Proof-of-concept: public PoC exists; no reported exploitation and no known simplification tools.
Confidentiality requirement (CR:X)
Not defined: insufficient information; scoring treats this like High (worst case).
Integrity requirement (IR:X)
Not defined: insufficient information; scoring treats this like High (worst case).
Availability requirement (AR:X)
Not defined: insufficient information; scoring treats this like High (worst case).
Modified attack vector (MAV:X)
Not defined: scoring uses the Base Attack Vector (AV).
Modified attack complexity (MAC:X)
Not defined: scoring uses the Base Attack Complexity (AC).
Modified attack requirements (MAT:X)
Not defined: scoring uses the Base Attack Requirements (AT).
Modified privileges required (MPR:X)
Not defined: scoring uses the Base Privileges Required (PR).
Modified user interaction (MUI:X)
Not defined: scoring uses the Base User Interaction (UI).
Modified vulnerable system confidentiality impact (MVC:X)
Not defined: scoring uses the Base VC metric.
Modified vulnerable system integrity impact (MVI:X)
Not defined: scoring uses the Base VI metric.
Modified vulnerable system availability impact (MVA:X)
Not defined: scoring uses the Base VA metric.
Modified subsequent system confidentiality impact (MSC:X)
Not defined: scoring uses the Base SC metric.
Modified subsequent system integrity impact (MSI:X)
Not defined: scoring uses the Base SI metric.
Modified subsequent system availability impact (MSA:X)
Not defined: scoring uses the Base SA metric.
Safety (supplemental) (S:X)
Not evaluated.
Automatable (supplemental) (AU:X)
Not evaluated.
Recovery (supplemental) (R:X)
Not evaluated.
Value density (supplemental) (V:X)
Not evaluated.
Vulnerability response effort (supplemental) (RE:X)
Not evaluated.
Provider urgency (supplemental) (U:X)
Not evaluated.
 — — [email protected]
9.8 3.1 CRITICAL
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.9 5.9 [email protected]

Weakness enumeration for CVE-2026-27606

GitHub Security Advisory for CVE-2026-27606

GHSA-mw96-cpmx-2vgc · Severity: high · Ecosystem: npm — Rollup 4 has Arbitrary File Write via Path Traversal

OS Trackers for CVE-2026-27606

vendor priority summary link
debian not yet assigned CVE-2026-27606 not yet assigned priority: Debian including 1 source packages (node-rollup), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): open 3, resolved 2. https://security-tracker.debian.org/tracker/CVE-2026-27606
redhat high — https://access.redhat.com/security/cve/CVE-2026-27606
suse high CVE-2026-27606 severity important: SUSE including 93 source package names (Multi-Linux-ManagerTools-Beta-SLE-Micro-release-5-159000.3.3.1, corepack20, …), 226 product×package rows across 32 product lines (Container suse/manager/5.0/x86_64/server, SUSE Linux Enterprise High Performance Computing 15 SP4-LTSS, … (32 product lines)): Known Not Affected 139, Fixed 72, First Fixed 15. https://www.suse.com/security/cve/CVE-2026-27606/
ubuntu medium CVE-2026-27606 medium priority: Ubuntu including 1 source packages (node-rollup), 5 status rows across 5 suites (focal, jammy, noble, questing, upstream): needs-triage 5. https://ubuntu.com/security/CVE-2026-27606

Affected software / configurations for CVE-2026-27606

Vendor Product Version Raw CPE
rollupjs rollup < 2.80.0 cpe:2.3:a:rollupjs:rollup:*:*:*:*:*:node.js:*:*
rollupjs rollup >= 3.0.0, < 3.30.0 cpe:2.3:a:rollupjs:rollup:*:*:*:*:*:node.js:*:*
rollupjs rollup >= 4.0.0, < 4.59.0 cpe:2.3:a:rollupjs:rollup:*:*:*:*:*:node.js:*:*

References for CVE-2026-27606

cvelogic Threat Intelligence