zip: Critical Parser Differential & Security Control Bypass via Dual-Header Inconsistencies (Zip Cloaking) Leading to Arbitrary File Overwrite & RCE

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS 4.0

10.0 · CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:L · score source

EPSS

• CVE-2026-115905: 0.32% estimated exploitation activity in the next 30 days; percentile 25.05 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Summary A critical architectural parser differential exists in the `zip` crate (` (&mut self, file: &mut ZipFile ) -> ZipResult { file.safe_prepare_path(&self.outpath, &mut outpath, None:: bool)>)?; let mut outfile = fs::File::create(&outpath)?; io::copy(file, &mut outfile)?; Ok(()) } ``` - `src/write.rs:L1552`: The crate explicitly exposes `shallow_copy_file`, an API that constructs dual-header desynchronizations by adding a new CDFH entry with an alias name pointing to an existing file without updating the original LFH.

Threat Scenario & Severity Justification (10.0 / 9.9 Critical) 1. Security Control Evasion: An adversary crafts a ZIP archive where: - Central Directory Header declares: `doc_report.pdf` (Clean document) - Local File Header declares: `cron_worker.sh` (Malicious root backdoor) 2. The archive is uploaded through a web portal or API endpoint protected by security gateways (WAF, Anti-Virus, Content Disarm & Reconstruction). The security gateway inspects the…

Published by the source

28 Oct 2026, 21:09 UTC

Last modified by the source

28 Oct 2026, 21:30 UTC

Source last checked

29 Oct 2026, 06:45 UTC

1. Revision 2 · amended · 29 Oct 2026

   Amended from osv record GHSA-m665-v7pm-7grj

2. Revision 1 · created · 28 Oct 2026

   Published from ghsa record GHSA-m665-v7pm-7grj

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# Patch Next advisory brief: CVE-2026-115905

Advisory: zip: Critical Parser Differential & Security Control Bypass via Dual-Header Inconsistencies (Zip Cloaking) Leading to Arbitrary File Overwrite & RCE
IDs: CVE-2026-115905, GHSA-m665-v7pm-7grj
Record: https://patchnext.com/advisories/cve-2026-115905 (revision 2, source checked 29 Oct 2026, 06:45 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Critical (CVSS 10.0)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: zip 9.0.5. A vendor fix does not mean a deployment is fixed.

## Affected components
- crates.io zip: affected < 9.0.5; fixed in 9.0.5

## Suggested inspection (read-only)
- crates.io zip: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on zip.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-m665-v7pm-7grj (GitHub-reviewed advisory GHSA-m665-v7pm-7grj lists affected ranges: crates.io zip >=0 <=9.0.4)
- Verified: https://osv.dev/vulnerability/GHSA-m665-v7pm-7grj (OSV record GHSA-m665-v7pm-7grj lists affected ranges: crates.io zip >=0 <9.0.5 (fixed))

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