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Fencer Vulns
high 7.1

CVE-2026-27970 json

Angular i18n vulnerable to Cross-Site Scripting (XSS)

published 2026-02-26 8 mo ago modified 2026-09-10 1 mo ago also GHSA-prjf-86w9-mfqv , EUVD-2026-8822

cvss
7.1
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.5%
EPSS 0.5% chance of exploitation in 30 days, percentile 46%
public exploits
0
none known

Summary

Angular is a development platform for building mobile and desktop web applications using TypeScript/JavaScript and other languages. Versions prior to 21.2.0, 21.1.16, 20.3.17, and 19.2.19 have a cross-Site scripting vulnerability in the Angular internationalization (i18n) pipeline. In ICU messages (International Components for Unicode), HTML from translated content was not properly sanitized and could execute arbitrary JavaScript. Angular i18n typically involves three steps, extracting all messages from an application in the source language, sending the messages to be translated, and then merging their translations back into the final source code. Translations are frequently handled by contracts with specific partner companies, and involve sending the source messages to a separate contractor before receiving final translations for display to the end user. If the returned translations have malicious content, it could be rendered into the application and execute arbitrary JavaScript. When successfully exploited, this vulnerability allows for execution of attacker controlled JavaScript in the application origin. Depending on the nature of the application being exploited this could lead to credential exfiltration and/or page vandalism. Several preconditions apply to the attack. The attacker must compromise the translation file (xliff, xtb, etc.). Unlike most XSS vulnerabilities, this issue is not exploitable by arbitrary users. An attacker must first compromise an application's translation file before they can escalate privileges into the Angular application client. The victim application must use Angular i18n, use one or more ICU messages, render an ICU message, and not defend against XSS via a safe content security policy. Versions 21.2.0, 21.1.6, 20.3.17, and 19.2.19 patch the issue. Until the patch is applied, developers should consider reviewing and verifying translated content received from untrusted third parties before incorporating it in an Angular application, enabling strict CSP controls to block unauthorized JavaScript from executing on the page, and enabling Trusted Types to enforce proper HTML sanitization.

Patch / fix

  • npm @angular/core 19.2.19, 20.3.17, 21.1.6, 21.2.0
  • angular angular 19.2.19, 20.3.17, 21.1.6

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-27970 updated cvss 7.1

@angular/core: Angular: Cross-site scripting via compromised translation files

  • Red Hat Enterprise Linux 8 intel-cmt-cat Red Hat Enterprise Linux 9 librbd1, librados2, intel-cmt-cat Red Hat Enterprise Linux 10 ceph, intel-cmt-cat
    affected: workaround, no fix available
  • Red Hat Fuse 7 io.apicurio-apicurito, io.syndesis-syndesis-parent
    affected: workaround, no fix planned “Will not fix”
  • Red Hat Ceph Storage 9.2 rhceph/rhceph-9-rhel10 1790843527
    fixed: vendor fix RHSA-2026:86618
  • Red Hat Advanced Cluster Management for Kubernetes 2 rhacm2/volsync-rhel9, rhacm2/volsync-operator-bundle Red Hat Ceph Storage 9.2 rhceph/alloy-rhel10 1790774976, rhceph/grafana-rhel10 1790774121, rhceph/keepalived-rhel10 1790842990, rhceph/oauth2-proxy-rhel10 1790774021, rhceph/snmp-notifier-rhel10 1790773439, rhceph/rhceph-haproxy-rhel10 1790846345
    not affected: vulnerable code not present
  • Red Hat Enterprise Linux 7 firefox
    not affected: vulnerable code not in execute path
  • Red Hat Enterprise Linux 8 firefox, mozjs60, thunderbird, dotnet5.0-build-reference-packages
    not affected: vulnerable code not present
  • Red Hat Enterprise Linux 9 gjs, polkit, firefox, firefox-x11, polkit-libs, thunderbird Red Hat Enterprise Linux 10 gjs, firefox, thunderbird Red Hat OpenShift AI (RHOAI) rhoai/odh-notebook-controller-rhel8, rhoai/odh-kf-notebook-controller-rhel8
    not affected: vulnerable code not in execute path

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
total
Assessed
8 mo ago

Exploit prediction

0.55% chance of exploitation in the next 30 days, higher than 46% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 4.0 7.6 CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N
CISA ADP 3.1 7.1 CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:L
CNA 4.0 7.6 CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:H/VI:H/VA:N/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
NVD 3.1 6.1 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
CNA 3.1 7.1 CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:L
GitHub 3.1 6.1 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

Affected packages

ecosystem package affected fixed in
npm @angular/core
>=21.2.0-next.0, <21.2.0
>=21.0.0-next.0, <21.1.6
>=20.0.0-next.0, <20.3.17
>=19.0.0-next.0, <19.2.19
<=18.2.14
21.2.0
21.1.6
20.3.17
19.2.19

Affected products

  • angular angular
  • Red Hat Red Hat Advanced Cluster Management for Kubernetes 2
  • Red Hat Red Hat Enterprise Linux 10
  • Red Hat Red Hat Enterprise Linux 7
  • Red Hat Red Hat Enterprise Linux 8
  • Red Hat Red Hat Enterprise Linux 9
  • Red Hat Red Hat Fuse 7
  • Red Hat Red Hat OpenShift AI (RHOAI)

Classification

Weakness
  • CWE-79 Improper Neutralization of Input During Web Page Generation

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.