CVE-2026-55451gettext-converter: Prototype pollution in js2i18next() via crafted translation keys
- 8.3HighCVSS base score
- 0.57%Exploitation in 30 daysEPSS · top 53% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- YesPublic exploitsa reference or SSVC says so
Description
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.
Public exploit
An exploit or proof of concept is public: anyone can try it against an unpatched system. A reference of the record is tagged as an exploit. CISA's SSVC rates its exploitation: a proof of concept is public.
Show the exploits1
References tagged exploit1 reference
- https://github.com/locize/gettext-converter/issues/15 (opens in a new tab)x_refsource_MISCexploit
Timeline
ID reserved
By GitHub_M
- 3 months later
· 3 months later
Published
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| GitHub_MCNA (assigner) | 4.0 | High8.3 | 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 |
| NVDNVD · Deferred | 4.0 | High8.3 | 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 |
- EPSS (exploitation in 30 days)
- 0.57% · top 53% of all CVEs (12 Nov 2026)
- CISA SSVC
- Exploitation: poc · Automatable: yes · Technical impact: partial
The list uses the assigner's score when there is one, then CISA's, then NVD's: High 8.3.
Affected products
- affected < 1.3.3
Affected packages
From reviewed advisories of the GitHub Advisory Database.
- npmgettext-converterGHSA-f4jp-rw7w-ccwg (opens in a new tab)
References
References4
- https://github.com/locize/gettext-converter/security/advisories/GHSA-f4jp-rw7w-ccwg (opens in a new tab)x_refsource_CONFIRM
- https://github.com/locize/gettext-converter/issues/15 (opens in a new tab)x_refsource_MISCexploit
- https://github.com/locize/gettext-converter/commit/df90c3b93e51faef68891d97b626544f619c5b31 (opens in a new tab)x_refsource_MISC
- https://github.com/locize/gettext-converter/releases/tag/v1.3.3 (opens in a new tab)x_refsource_MISC
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2026-77634 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisory GHSA-f4jp-rw7w-ccwg (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2026-55451)Record last updated .