CVE-2019-18222 [Medium] | Security Vulnerability in Mbed Crypto

The ECDSA signature implementation in ecdsa.c in Arm Mbed Crypto 2.1 and Mbed TLS through 2.19.1 does not reduce the blinded scalar before computing the inverse, which allows a local attacker to recover the private key via side-channel attacks.

#	Date	Old EPSS score	New EPSS score	Delta (New - Old)
1	2026-02-26	0.15%	0.13%	-0.02%
2	2026-02-21	0.13%	0.15%	+0.03%
3	2026-01-04	—	0.13%	—

Date

Old EPSS score

New EPSS score

Delta (New - Old)

2026-02-26

0.15%

0.13%

-0.02%

2026-02-21

0.13%

0.15%

+0.03%

2026-01-04

—

0.13%

—

Base score	Version	Severity	Vector	Exploitability	Impact	Score source
4.7	3.1	MEDIUM	`CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N` Click to expand Attack vector (AV:L) They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by. Attack complexity (AC:H) Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work. Privileges required (PR:L) A normal user session is enough; they don’t have to be admin. User interaction (UI:N) Nobody has to click “OK” or open a trap file; it can work without a victim helping. 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:N) Data isn’t meaningfully altered or forged. Availability (A:N) Service keeps running; no real outage angle.	1.0	3.6	[email protected]
1.9	2.0	LOW	`AV:L/AC:M/Au:N/C:P/I:N/A:N` Click to expand Access vector (AV:L) Requires local access to the target system. Access complexity (AC:M) Exploitation needs some favorable conditions, but not exceptional ones. Authentication (AU:N) No authentication is required. Confidentiality impact (C:P) Partial confidentiality impact. Integrity impact (I:N) No integrity impact. Availability impact (A:N) No availability impact.	3.4	2.9	[email protected]

Base score

Version

Severity

Vector

Exploitability

Impact

Score source

4.7

3.1

MEDIUM

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

Attack vector (AV:L): They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:H): Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
Privileges required (PR:L): A normal user session is enough; they don’t have to be admin.
User interaction (UI:N): Nobody has to click “OK” or open a trap file; it can work without a victim helping.
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:N): Data isn’t meaningfully altered or forged.
Availability (A:N): Service keeps running; no real outage angle.

1.0

3.6

[email protected]

1.9

2.0

LOW

AV:L/AC:M/Au:N/C:P/I:N/A:N Click to expand

Access vector (AV:L): Requires local access to the target system.
Access complexity (AC:M): Exploitation needs some favorable conditions, but not exceptional ones.
Authentication (AU:N): No authentication is required.
Confidentiality impact (C:P): Partial confidentiality impact.
Integrity impact (I:N): No integrity impact.
Availability impact (A:N): No availability impact.

3.4

2.9

[email protected]

OS Trackers for CVE-2019-18222

vendor	priority	summary	link
`alpine`	medium	CVE-2019-18222: 2 source package rows (mbedtls, mbedtls2); 14 state rows across 14 repos (3.10-main, 3.11-main, 3.12-main, 3.17-main, 3.18-main, 3.19-main, 3.20-community, 3.20-main, 3.21-community, 3.21-main, 3.22-community, 3.22-main, edge-community, edge-main); fixed 14, open 0.	https://security.alpinelinux.org/vuln/CVE-2019-18222
`debian`	not yet assigned	CVE-2019-18222 not yet assigned priority: Debian including 1 source packages (mbedtls), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5.	https://security-tracker.debian.org/tracker/CVE-2019-18222
`ubuntu`	medium	CVE-2019-18222 medium priority: Ubuntu including 1 source packages (mbedtls), 17 status rows across 17 suites (bionic, eoan, focal, groovy, hirsute, impish, jammy, kinetic, lunar, mantic, noble, oracular, plucky, questing, trusty, upstream, xenial): not-affected 12, needs-triage 2, DNE 1, ignored 1, released 1.	https://ubuntu.com/security/CVE-2019-18222

Affected software / configurations for CVE-2019-18222

Vendor	Product	Version	Raw CPE
arm	mbed_crypto	< 3.0.0	cpe:2.3:a:arm:mbed_crypto::::::::
arm	mbed_tls	< 2.7.13	cpe:2.3:a:arm:mbed_tls::::::::
arm	mbed_tls	>= 2.8.0, < 2.16.4	cpe:2.3:a:arm:mbed_tls::::::::
arm	mbed_tls	>= 2.17.0, < 2.20.0	cpe:2.3:a:arm:mbed_tls::::::::
fedoraproject	fedora	30	cpe:2.3:o:fedoraproject:fedora:30:::::::*
fedoraproject	fedora	31	cpe:2.3:o:fedoraproject:fedora:31:::::::*
debian	debian_linux	10.0	cpe:2.3:o:debian:debian_linux:10.0:::::::*

References for CVE-2019-18222

URL	Tags
https://lists.debian.org/debian-lts-announce/2022/12/msg00036.html	Mailing List Third Party Advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/A3GWQNONS7GRORXZJ7MOJFUEJ2ZJ4OUW/	Mailing List Third Party Advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/NGDACU65MYZXXVPQP2EBHUJGOR4RWLVY/	Mailing List Third Party Advisory
https://tls.mbed.org/tech-updates/security-advisories	Vendor Advisory
https://tls.mbed.org/tech-updates/security-advisories/mbedtls-security-advisory-2019-12	Vendor Advisory

URL

CVE-2019-18222

Exploit prediction scoring system (EPSS) score for CVE-2019-18222

Common vulnerability scoring system (CVSS) metrics for CVE-2019-18222

Weakness enumeration for CVE-2019-18222

OS Trackers for CVE-2019-18222

Affected software / configurations for CVE-2019-18222

References for CVE-2019-18222