CVE-2026-27970 [High] | XSS in Angular

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.

#	Date	Old EPSS score	New EPSS score	Delta (New - Old)
1	2026-06-30	0.43%	0.47%	+0.03%
2	2026-06-15	0.06%	0.43%	+0.38%
3	2026-05-05	—	0.06%	—

Date

Old EPSS score

New EPSS score

Delta (New - Old)

2026-06-30

0.43%

0.47%

+0.03%

2026-06-15

0.06%

0.43%

+0.38%

2026-05-05

—

0.06%

—

Base score	Version	Severity	Vector	Exploitability	Impact	Score source
7.6	4.0	HIGH	`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` Click to expand Attack vector (AV:N) Could be attacked over the internet or any normal routed network. Attack complexity (AC:L) Exploitation conditions are straightforward and stable. Attack requirements (AT:P) Additional preconditions must be present for exploitation. Privileges required (PR:N) No privileges are required. User interaction (UI:P) A user has to participate (for example click/open/approve). Vulnerable system confidentiality impact (VC:H) High confidentiality impact on the vulnerable system. Vulnerable system integrity impact (VI:H) High integrity impact on the vulnerable system. Vulnerable system availability impact (VA:N) No availability impact on the vulnerable system. Subsequent system confidentiality impact (SC:N) No confidentiality impact on subsequent systems. Subsequent system integrity impact (SI:N) No integrity impact on subsequent systems. Subsequent system availability impact (SA:N) No availability impact on subsequent systems. Exploit maturity (threat) (E:X) Not defined: no reliable threat intelligence; scoring assumes the worst case (equivalent to Attacked). Confidentiality requirement (CR:X) Not defined: insufficient information; scoring treats this like High (worst case). Integrity requirement (IR:X) Not defined: insufficient information; scoring treats this like High (worst case). Availability requirement (AR:X) Not defined: insufficient information; scoring treats this like High (worst case). Modified attack vector (MAV:X) Not defined: scoring uses the Base Attack Vector (AV). Modified attack complexity (MAC:X) Not defined: scoring uses the Base Attack Complexity (AC). Modified attack requirements (MAT:X) Not defined: scoring uses the Base Attack Requirements (AT). Modified privileges required (MPR:X) Not defined: scoring uses the Base Privileges Required (PR). Modified user interaction (MUI:X) Not defined: scoring uses the Base User Interaction (UI). Modified vulnerable system confidentiality impact (MVC:X) Not defined: scoring uses the Base VC metric. Modified vulnerable system integrity impact (MVI:X) Not defined: scoring uses the Base VI metric. Modified vulnerable system availability impact (MVA:X) Not defined: scoring uses the Base VA metric. Modified subsequent system confidentiality impact (MSC:X) Not defined: scoring uses the Base SC metric. Modified subsequent system integrity impact (MSI:X) Not defined: scoring uses the Base SI metric. Modified subsequent system availability impact (MSA:X) Not defined: scoring uses the Base SA metric. Safety (supplemental) (S:X) Not evaluated. Automatable (supplemental) (AU:X) Not evaluated. Recovery (supplemental) (R:X) Not evaluated. Value density (supplemental) (V:X) Not evaluated. Vulnerability response effort (supplemental) (RE:X) Not evaluated. Provider urgency (supplemental) (U:X) Not evaluated.	—	—	[email protected]
6.1	3.1	MEDIUM	`CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N` Click to expand Attack vector (AV:N) Could be attacked over the internet or any normal routed network—not just someone sitting at the machine. Attack complexity (AC:L) Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup. Privileges required (PR:N) No account or special rights needed—anonymous or random user is enough. User interaction (UI:R) A real person has to do something—click, install, enable—otherwise it doesn’t land. Scope (S:C) Breaking this can reach past the original component and bite other resources—bigger blast radius. Confidentiality (C:L) Some sensitive info could get out, but not a total data dump. Integrity (I:L) Attackers could change some data, but it’s limited—not everything goes. Availability (A:N) Service keeps running; no real outage angle.	2.8	2.7	[email protected]
7.1	3.1	HIGH	`CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:L` Click to expand Attack vector (AV:N) Could be attacked over the internet or any normal routed network—not just someone sitting at the machine. Attack complexity (AC:H) Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work. Privileges required (PR:N) No account or special rights needed—anonymous or random user is enough. User interaction (UI:R) A real person has to do something—click, install, enable—otherwise it doesn’t land. Scope (S:U) Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems. Confidentiality (C:H) Serious risk that confidential data gets exposed in a big way. Integrity (I:H) They could widely tamper with or forge data—trust in the data is badly hurt. Availability (A:L) Might cause slowdowns, glitches, or partial disruption—not a full brick.	1.6	5.5	0b0ca135-0b70-47e7-9f44-1890c2a1c46c

Base score

Version

Severity

Vector

Exploitability

Impact

Score source

7.6

4.0

HIGH

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

Click to expand

Attack vector (AV:N): Could be attacked over the internet or any normal routed network.
Attack complexity (AC:L): Exploitation conditions are straightforward and stable.
Attack requirements (AT:P): Additional preconditions must be present for exploitation.
Privileges required (PR:N): No privileges are required.
User interaction (UI:P): A user has to participate (for example click/open/approve).
Vulnerable system confidentiality impact (VC:H): High confidentiality impact on the vulnerable system.
Vulnerable system integrity impact (VI:H): High integrity impact on the vulnerable system.
Vulnerable system availability impact (VA:N): No availability impact on the vulnerable system.
Subsequent system confidentiality impact (SC:N): No confidentiality impact on subsequent systems.
Subsequent system integrity impact (SI:N): No integrity impact on subsequent systems.
Subsequent system availability impact (SA:N): No availability impact on subsequent systems.
Exploit maturity (threat) (E:X): Not defined: no reliable threat intelligence; scoring assumes the worst case (equivalent to Attacked).
Confidentiality requirement (CR:X): Not defined: insufficient information; scoring treats this like High (worst case).
Integrity requirement (IR:X): Not defined: insufficient information; scoring treats this like High (worst case).
Availability requirement (AR:X): Not defined: insufficient information; scoring treats this like High (worst case).
Modified attack vector (MAV:X): Not defined: scoring uses the Base Attack Vector (AV).
Modified attack complexity (MAC:X): Not defined: scoring uses the Base Attack Complexity (AC).
Modified attack requirements (MAT:X): Not defined: scoring uses the Base Attack Requirements (AT).
Modified privileges required (MPR:X): Not defined: scoring uses the Base Privileges Required (PR).
Modified user interaction (MUI:X): Not defined: scoring uses the Base User Interaction (UI).
Modified vulnerable system confidentiality impact (MVC:X): Not defined: scoring uses the Base VC metric.
Modified vulnerable system integrity impact (MVI:X): Not defined: scoring uses the Base VI metric.
Modified vulnerable system availability impact (MVA:X): Not defined: scoring uses the Base VA metric.
Modified subsequent system confidentiality impact (MSC:X): Not defined: scoring uses the Base SC metric.
Modified subsequent system integrity impact (MSI:X): Not defined: scoring uses the Base SI metric.
Modified subsequent system availability impact (MSA:X): Not defined: scoring uses the Base SA metric.
Safety (supplemental) (S:X): Not evaluated.
Automatable (supplemental) (AU:X): Not evaluated.
Recovery (supplemental) (R:X): Not evaluated.
Value density (supplemental) (V:X): Not evaluated.
Vulnerability response effort (supplemental) (RE:X): Not evaluated.
Provider urgency (supplemental) (U:X): Not evaluated.

—

[email protected]

6.1

3.1

MEDIUM

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N Click to expand

Attack vector (AV:N): Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L): Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N): No account or special rights needed—anonymous or random user is enough.
User interaction (UI:R): A real person has to do something—click, install, enable—otherwise it doesn’t land.
Scope (S:C): Breaking this can reach past the original component and bite other resources—bigger blast radius.
Confidentiality (C:L): Some sensitive info could get out, but not a total data dump.
Integrity (I:L): Attackers could change some data, but it’s limited—not everything goes.
Availability (A:N): Service keeps running; no real outage angle.

2.8

2.7

[email protected]

7.1

3.1

HIGH

CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:L Click to expand

Attack vector (AV:N): Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:H): Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
Privileges required (PR:N): No account or special rights needed—anonymous or random user is enough.
User interaction (UI:R): A real person has to do something—click, install, enable—otherwise it doesn’t land.
Scope (S:U): Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H): Serious risk that confidential data gets exposed in a big way.
Integrity (I:H): They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:L): Might cause slowdowns, glitches, or partial disruption—not a full brick.

1.6

5.5

0b0ca135-0b70-47e7-9f44-1890c2a1c46c

OS Trackers for CVE-2026-27970

vendor	priority	summary	link
`debian`	not yet assigned	CVE-2026-27970 not yet assigned priority: Debian including 1 source packages (angular.js), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): undetermined 5.	https://security-tracker.debian.org/tracker/CVE-2026-27970
`redhat`	high	—	https://access.redhat.com/security/cve/CVE-2026-27970
`ubuntu`	medium	CVE-2026-27970 medium priority: Ubuntu including 1 source packages (angular.js), 7 status rows across 7 suites (bionic, focal, jammy, noble, questing, upstream, xenial): needs-triage 7.	https://ubuntu.com/security/CVE-2026-27970

Affected software / configurations for CVE-2026-27970

Vendor	Product	Version	Raw CPE
angular	angular	< 19.2.19	cpe:2.3:a:angular:angular::::::node.js::*
angular	angular	>= 20.0.0, < 20.3.17	cpe:2.3:a:angular:angular::::::node.js::*
angular	angular	>= 21.0.0, < 21.1.6	cpe:2.3:a:angular:angular::::::node.js::*
angular	angular	21.2.0	cpe:2.3:a:angular:angular:21.2.0:next0::::node.js::*
angular	angular	21.2.0	cpe:2.3:a:angular:angular:21.2.0:next1::::node.js::*
angular	angular	21.2.0	cpe:2.3:a:angular:angular:21.2.0:next2::::node.js::*
angular	angular	21.2.0	cpe:2.3:a:angular:angular:21.2.0:next3::::node.js::*
angular	angular	21.2.0	cpe:2.3:a:angular:angular:21.2.0:rc0::::node.js::*

References for CVE-2026-27970

URL	Tags
https://github.com/angular/angular/commit/306f367899dfc2e04238fecd3455547b5d54075d	Patch
https://github.com/angular/angular/commit/7d58b798c626bb0e4e5f89ca8affdce4f352b232	Patch
https://github.com/angular/angular/commit/b85830953281ff3a1a77bbfe69019d352d509c93	Patch
https://github.com/angular/angular/pull/67183	Issue Tracking Patch
https://github.com/angular/angular/security/advisories/GHSA-prjf-86w9-mfqv	Mitigation Patch Vendor Advisory
https://access.redhat.com/security/cve/CVE-2026-27970
https://bugzilla.redhat.com/show_bug.cgi?id=2442934
https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-27970.json

URL

CVE-2026-27970 | Angular i18n vulnerable to Cross-Site Scripting (XSS)

Exploit prediction scoring system (EPSS) score for CVE-2026-27970

Common vulnerability scoring system (CVSS) metrics for CVE-2026-27970

Weakness enumeration for CVE-2026-27970

GitHub Security Advisory for CVE-2026-27970

OS Trackers for CVE-2026-27970

Affected software / configurations for CVE-2026-27970

References for CVE-2026-27970