GHSA-f4jp-rw7w-ccwgPublished

gettext-converter: Prototype pollution in js2i18next() via crafted translation keys

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cve-program · CVE-2026-55451

Published

gettext-converter provides gettext resource conversion utilities for JavaScript. Prior to 1.3.3, js2i18next() in lib/js2i18next.js splits nested translation keys using options.keyseparator, whose default value consists of two number signs, and uses each segment as a dynamic object key without rejecting __proto__, constructor, or prototype. When an application converts untrusted PO or i18next translation data, a __proto__ segment resolves Object.prototype as the nested write target and Object.assign writes attacker-controlled translated properties onto the process-wide prototype. The resulting prototype pollution can cause denial of service and may enable application-dependent follow-on attacks. This issue is fixed in version 1.3.3.

Source published: 14 Sep 2026 16:49:36 UTC
Source modified: 14 Sep 2026 18:53:39 UTC
Saved here: 23 Oct 2026 15:48:27 UTC
Source terms: CVE Program Terms of Use

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CVSS 4.0 · 8.3 CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:H/VA:H/SC:N/SI:N/SA:N

euvd · EUVD-2026-77634

Published

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EUVD source date text has no stated timezone and is retained without inventing a UTC instant. Related bulletin membership is not an alias, common cause or applicability claim. A missing vector with a zero score is treated as unrated. Complete vendor/product and underlying source evidence remains in the original JSON.

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datePublished: Sep 14, 2026, 4:49:36 PM

dateUpdated: Sep 14, 2026, 6:53:39 PM

Source published: Sep 14, 2026, 4:49:36 PM (timezone not stated)
Source modified: Sep 14, 2026, 6:53:39 PM (timezone not stated)
Saved here: 11 Nov 2026 17:11:02 UTC
Source terms: ENISA EUVD · source terms and attribution apply

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EUVD CVSS 4.0 · 8.3 CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:H/VA:H/SC:N/SI:N/SA:N

nvd · CVE-2026-55451

Published

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NVD analysis and CPE criteria are source context, not proof that a package or your environment is affected. Complete affected data, logical configurations and SSVC are retained in the original JSON.

Source analysis status: Deferred

Weakness classifications: CWE-1321

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published: 2026-09-14T17:17:48.383

lastModified: 2026-09-30T19:57:08.043

Source published: 14 Sep 2026 17:17:48 UTC
Source modified: 30 Sep 2026 19:57:08 UTC
Saved here: 25 Oct 2026 13:17:34 UTC
Source terms: NIST NVD usage terms; underlying source attribution retained

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CVSS 4.0 · [email protected] · Secondary · 8.3 CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/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

osv · GHSA-f4jp-rw7w-ccwg

Published

### Impact `js2i18next()` is vulnerable to prototype pollution. When converting translations, it splits nested keys on the key separator (default `##`) and uses each segment as a dynamic object key while building the output object. A key whose segment is `__proto__` (e.g. `__proto__##gcPolluted`) causes the converter to resolve `Object.prototype` as the nested write target and assign the translated value onto it, polluting `Object.prototype` for the whole runtime. Any application that converts translation data (PO / i18next JS objects) originating from an untrusted or user-controlled source is affected. Prototype pollution can lead to denial of service and, depending on the surrounding application, may enable further attacks. ### Patches Fixed in `[email protected]`. Key segments equal to `__proto__`, `constructor`, or `prototype` are now rejected before being used as dynamic object keys. ### Workarounds Upgrade to `1.3.3`. If upgrading is not immediately possible, sanitize/validate translation keys before passing them to `js2i18next()` and reject any key whose `##`-separated segments include `__proto__`, `constructor`, or `prototype`.

Source published: 20 Aug 2026 20:11:13 UTC
Source modified: 20 Aug 2026 20:26:04 UTC
Saved here: 24 Oct 2026 13:17:17 UTC
Source terms: GitHub Advisory Database · CC-BY-4.0

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Source: osv · GitHub Advisory Database · CC-BY-4.0. The publisher's wording is preserved. ChangeIntel groups the information and labels changes. The JSON record includes additional source fields.

CVSS_V4 · CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N

Publisher rating · MODERATE