CVE-2026-115905: zip: Critical Parser Differential & Security Control Bypass via Dual-Header Inconsistencies (Zip Cloaking) Leading to Arbitrary File Overwrite & RCE

Should you act?

Critical and remotely reachable

No known exploitation yet, but it is network-reachable without credentials. This signal is computed from CISA KEV, EPSS and CVSS data; it is not an editorial verdict.

• Not in CISA KEV, but CISA’s SSVC assessment records a public proof-of-concept, so attack code exists.
• EPSS 0.3%, percentile 25: FIRST’s model estimates a 0.3% chance of exploitation activity in the next 30 days, higher than 25% of all scored CVEs (low). EPSS is a probability, not a verdict.
• Remotely reachable with no login and no user interaction. If the vulnerable service is exposed to the internet, prioritize it.
• Only applies if your dependency tree includes zip (crates.io (Rust)) <= 9.0.4, fixed in 9.0.5. Check your lockfile, including transitive dependencies.

What it is

zip is a zip library for Rust that supports reading and writing simple ZIP files. Through 9.0.4, ZipArchive treats Central Directory File Header filenames as authoritative while ZipStreamReader extracts using Local File Header filenames without reconciling the duplicate metadata in src/read/stream.rs. A crafted archive can therefore appear benign to a component that inspects the central directory but cause a streaming extractor to write a different attacker-selected path and content, potentially overwriting files used by a downstream service. This issue is fixed in version 9.0.5.

From the GitHub advisory

Summary A critical architectural parser differential exists in the zip crate (

This discrepancy enables ZIP archives to appear to have different file paths and contents according to which tool is reading them.

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Details

Architectural Root Cause In the PKWARE ZIP archive format, every file entry is defined in two distinct locations: 1. Local File Header (LFH): Precedes the compressed payload of each file in the body of the archive. 2. Central Directory File Header (CDFH): Stored in a contiguous index at the end of the archive.

Weakness type: CWE-20, CWE-436.

Product: zip (crates.io (Rust)) · Assigned by: GitHub_M · Published: 2026-10-26

Affected and fixed versions

Severity scores

• Attack vector: network (remotely reachable)
• Attack complexity: low
• Attack requirements: none
• Privileges required: none (no login)
• User interaction: none

CVSS measures how bad a flaw is if exploited, not how likely exploitation is. Read it next to the exploitation data below.

Exploitation and urgency

• CISA KEV: not listed (no confirmed in-the-wild exploitation known to CISA).
• CISA SSVC assessment: exploitation poc, automatable yes, technical impact total.
• FIRST EPSS (model of 2026-11-04): 0.32% probability of exploitation activity in the next 30 days; percentile 25.

Timeline

• 2026-10-26 — CVE record published by GitHub_M
• 2026-10-28 — GitHub-reviewed advisory GHSA-m665-v7pm-7grj published (critical)
• 2026-11-02 — CVE record last updated

Sources and references

Original sources first. Version and fix details should always be confirmed against the vendor or project advisory.

Vulnerability records

1. GitHub Advisory GHSA-m665-v7pm-7grj github.com
2. CVE.org record CVE-2026-115905 cve.org
3. NVD entry CVE-2026-115905 nvd.nist.gov

Other references from the CVE record and advisory

1. github.com github.com
2. github.com github.com
3. github.com github.com

Critical crates.io (Rust) advisories · Today’s Security Digest