# CVE-2026-53655: node-tar applies PAX size override to intermediary GNU long-name/long-link headers, causing tar parser interpretation differential (file smuggling) > Attackers can craft archives that bypass security scanners by exploiting parser differences in node-tar, hiding malicious files from inspection tools. - **Severity:** Medium 6.9 (`CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N`) - **Exploited in the wild:** Not known - **Login needed:** Not needed - **Attackable:** Local or same network only - **Victim action needed:** Not needed - **Fix available:** Yes - **Published:** 22 Jun 2026 - **Updated:** 23 Jun 2026 - **Also known as:** CLEANSTART-2026-AO11552, CLEANSTART-2026-EK83190, CLEANSTART-2026-KF01846, CLSA-2026-1782089813, DEBIAN-CVE-2026-53655, ECHO-28bc-03c1-ad35, GHSA-vmf3-w455-68vh, MINI-2c36-3pg4-xxr3, MINI-2c5g-jf26-2fj4, MINI-3j68-3mfr-w88q, MINI-4m73-c3wf-h947, MINI-53g8-45wc-wpcv, MINI-5c8r-575q-xrmv, MINI-5cgq-g545-g9mw, MINI-6g36-mr8p-j769, MINI-98xm-ccwh-x2qv, MINI-9fcx-w2qf-xjpw, MINI-c6wr-rfgj-979v, MINI-c962-p5jx-fj7p, MINI-f2rc-27vq-54cr, MINI-f7jf-mr4f-xwpc, MINI-g3r2-j2rj-f376, MINI-g569-8g4c-996h, MINI-gj5p-3347-mpg3, MINI-h39m-f2jg-g827, MINI-hwqp-r88p-m22x, MINI-j858-7rhr-mg4x, MINI-jjq2-7f8f-8frj, MINI-jxj7-qgjh-99g9, MINI-m39p-343c-mc65, MINI-mmjx-q764-p9xp, MINI-mv7m-8qrp-x9jp, MINI-p862-7678-mr59, MINI-p9w2-8rfr-p5jm, MINI-q7p3-838r-v3cv, MINI-r7hj-wfvw-4xgv, MINI-v5cv-qpv2-v432, MINI-w5vv-6wqv-2w92, MINI-x37c-g58m-4m5m, ROOT-APP-NPM-CVE-2026-53655, UBUNTU-CVE-2026-53655 ## What is CVE-2026-53655? CVE-2026-53655 is a medium-severity vulnerability in isaacs node-tar, published on 22 Jun 2026. It can only be exploited from the same machine or local network, with no action from the victim. ### Official description node-tar is a full-featured Tar for Node.js. Prior to 7.5.16, tar (node-tar) applies a PAX extended header's size= record (and other PAX overrides) to the next header entry of any type, including intermediary metadata headers such as a GNU long-name (L) or long-link (K) entry. Per POSIX pax, a PAX extended header (x) describes the next file entry, not the intermediary extension headers that may sit between the x header and the file it annotates. Because node-tar lets the PAX size override the byte length of an intervening L/K/x header, an attacker can desynchronize node-tar's stream cursor relative to every other mainstream tar implementation (GNU tar, libarchive/bsdtar, Python tarfile, and the now-fixed tar-rs / astral-tokio-tar). The result is a tar parser interpretation differential (CWE-436): a single crafted archive yields a different set of members under node-tar than under the reference tar tools. An attacker can use this to hide a member from one parser while it is visible to another, which defeats security tooling whose scanner and extractor disagree on archive contents (e.g. a malware/secret scanner that lists entries with one library while a downstream step extracts with another) This vulnerability is fixed in 7.5.16. Weakness: CWE-436 (Interpretation Conflict) ## Which versions are affected by CVE-2026-53655? 2 open source packages ship an affected version, including tar. It affects 1 product. | Package | Ecosystem | Affected | Fixed in | | --- | --- | --- | --- | | `tar` | npm | All versions | 7.5.16 | | `tar` | npm | All versions | 7.5.16 | Products: Isaacs Tar. ## How do I fix CVE-2026-53655? Upgrade tar to 7.5.16 or later. ## Is CVE-2026-53655 being exploited? It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-53655 exists. ## Other vulnerabilities in isaacs node-tar - [CVE-2026-59873](https://insights.sbomify.com/CVE-2026-59873/): node-tar: Decompression/parse DoS via unlimited input (critical 9.2) - [CVE-2026-23950](https://insights.sbomify.com/CVE-2026-23950/): node-tar has Race Condition in Path Reservations via Unicode Ligature Collisions on macOS APFS (high 8.8) - [CVE-2026-59874](https://insights.sbomify.com/CVE-2026-59874/): node-tar: Negative tar entry size causes infinite loop in archive replace (high 8.7) - [CVE-2026-31802](https://insights.sbomify.com/CVE-2026-31802/): node-tar Symlink Path Traversal via Drive-Relative Linkpath (high 8.2) - [CVE-2026-29786](https://insights.sbomify.com/CVE-2026-29786/): node-tar: Hardlink Path Traversal via Drive-Relative Linkpath (high 8.2) ## Fix prompt for AI coding agents ```text Check this codebase for CVE-2026-53655 and fix it if it is affected. What it is: CVE-2026-53655 is a medium-severity vulnerability in isaacs node-tar, published on 22 Jun 2026. It can only be exploited from the same machine or local network, with no action from the victim. Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-53655 exists. Affected packages and fixed versions: - tar (npm): affected all versions; fixed in 7.5.16 - tar (npm): affected all versions; fixed in 7.5.16 Task: 1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies. 2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it. 3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead. 4. Run the tests and summarise what changed and why. 5. If nothing in the project is affected, say so and change nothing. Reference: https://insights.sbomify.com/CVE-2026-53655/ (Markdown: https://insights.sbomify.com/CVE-2026-53655/index.md) ``` ## Sources - CVE record: https://www.cve.org/CVERecord?id=CVE-2026-53655 - NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-53655 - OSV: https://osv.dev/vulnerability/CVE-2026-53655 --- From sbomify Insights: https://insights.sbomify.com/CVE-2026-53655/ Summaries are generated and may contain mistakes; the official description above is the record.