CVE-2019-11766 [Critical] | Out-of-bounds Read in Dhcpcd

CVE-2019-11766 is rated High Risk (68/100): CVSS Critical severity, with medium exploitation likelihood (EPSS 2.10%). EPSS rose +1.07% over the last day, indicating growing attacker interest. High exploitation likelihood—assess exposure and prioritize remediation.

#	Date	Old EPSS score	New EPSS score	Delta (New - Old)
1	2026-06-15	1.03%	2.10%	+1.07%
2	2026-05-12	0.73%	1.03%	+0.30%
3	2026-04-05	—	0.73%	—

Date

Old EPSS score

New EPSS score

Delta (New - Old)

2026-06-15

1.03%

2.10%

+1.07%

2026-05-12

0.73%

1.03%

+0.30%

2026-04-05

—

0.73%

—

Base score	Version	Severity	Vector	Exploitability	Impact	Score source
9.8	3.1	CRITICAL	`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H` 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: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:H) They could widely tamper with or forge data—trust in the data is badly hurt. Availability (A:H) Could take the service down hard or make it unusable for people who depend on it.	3.9	5.9	[email protected]
7.5	2.0	HIGH	`AV:N/AC:L/Au:N/C:P/I:P/A:P` Click to expand Access vector (AV:N) Can be exploited remotely over network reachability. Access complexity (AC:L) Exploitation conditions are straightforward and predictable. Authentication (AU:N) No authentication is required. Confidentiality impact (C:P) Partial confidentiality impact. Integrity impact (I:P) Partial integrity impact. Availability impact (A:P) Partial availability impact.	10.0	6.4	[email protected]

Base score

Version

Severity

Vector

Exploitability

Impact

Score source

9.8

3.1

CRITICAL

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H 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: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:H): They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H): Could take the service down hard or make it unusable for people who depend on it.

3.9

5.9

[email protected]

7.5

2.0

HIGH

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

Access vector (AV:N): Can be exploited remotely over network reachability.
Access complexity (AC:L): Exploitation conditions are straightforward and predictable.
Authentication (AU:N): No authentication is required.
Confidentiality impact (C:P): Partial confidentiality impact.
Integrity impact (I:P): Partial integrity impact.
Availability impact (A:P): Partial availability impact.

10.0

6.4

[email protected]

OS Trackers for CVE-2019-11766

vendor	priority	summary	link
`debian`	not yet assigned	CVE-2019-11766 not yet assigned priority: Debian including 1 source packages (dhcpcd5), 2 status rows across 2 suites (bookworm, bullseye): resolved 2.	https://security-tracker.debian.org/tracker/CVE-2019-11766
`suse`	medium	CVE-2019-11766 severity moderate: SUSE including 1 source package names (dhcpcd), 5 product×package rows across 5 product lines (SLES for SAP Applications 11 SP3, SUSE Linux Enterprise Server 11 SP1 for Teradata, … (5 product lines)): Known Not Affected 5.	https://www.suse.com/security/cve/CVE-2019-11766/
`ubuntu`	medium	CVE-2019-11766 medium priority: Ubuntu including 1 source packages (dhcpcd5), 19 status rows across 19 suites (bionic, cosmic, disco, eoan, focal, groovy, hirsute, impish, jammy, kinetic, lunar, mantic, noble, oracular, plucky, questing, trusty, upstream, xenial): released 9, DNE 5, ignored 2, needed 2, needs-triage 1.	https://ubuntu.com/security/CVE-2019-11766

Affected software / configurations for CVE-2019-11766

Vendor	Product	Version	Raw CPE
dhcpcd_project	dhcpcd	< 6.11.7	cpe:2.3:a:dhcpcd_project:dhcpcd::::::::
dhcpcd_project	dhcpcd	>= 7.0.0, < 7.2.2	cpe:2.3:a:dhcpcd_project:dhcpcd::::::::
debian	debian_linux	8.0	cpe:2.3:o:debian:debian_linux:8.0:::::::*
debian	debian_linux	9.0	cpe:2.3:o:debian:debian_linux:9.0:::::::*
debian	debian_linux	10.0	cpe:2.3:o:debian:debian_linux:10.0:::::::*

References for CVE-2019-11766

URL	Tags
http://www.securityfocus.com/bid/108172	Broken Link
https://bugs.debian.org/928440	Mailing List Patch Third Party Advisory
https://roy.marples.name/archives/dhcpcd-discuss/0002428.html	Patch Vendor Advisory
https://roy.marples.name/cgit/dhcpcd.git/commit/?h=dhcpcd-7&id=896ef4a54b0578985e5e1360b141593f1d62837b	Mailing List Patch Vendor Advisory
https://roy.marples.name/cgit/dhcpcd.git/commit/?h=dhcpcd-7&id=c1ebeaafeb324bac997984abdcee2d4e8b61a8a8	Mailing List Patch Vendor Advisory

URL

CVE-2019-11766

Exploit prediction scoring system (EPSS) score for CVE-2019-11766

Common vulnerability scoring system (CVSS) metrics for CVE-2019-11766

Weakness enumeration for CVE-2019-11766

OS Trackers for CVE-2019-11766

Affected software / configurations for CVE-2019-11766

References for CVE-2019-11766