CVE-2019-11049 [Medium] | Security Vulnerability in Php

In PHP versions 7.3.x below 7.3.13 and 7.4.0 on Windows, when supplying custom headers to mail() function, due to mistake introduced in commit 78f4b4a2dcf92ddbccea1bb95f8390a18ac3342e, if the header is supplied in lowercase, this can result in double-freeing certain memory locations.

#	Date	Old EPSS score	New EPSS score	Delta (New - Old)
1	2026-03-25	2.73%	2.80%	+0.07%
2	2026-03-04	1.64%	2.73%	+1.10%
3	2026-03-01	—	1.64%	—

Date

Old EPSS score

New EPSS score

Delta (New - Old)

2026-03-25

2.73%

2.80%

+0.07%

2026-03-04

1.64%

2.73%

+1.10%

2026-03-01

—

1.64%

—

Base score	Version	Severity	Vector	Exploitability	Impact	Score source
6.5	3.1	MEDIUM	`CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/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: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: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:N) Doesn’t really leak secrets in a meaningful way. Integrity (I:L) Attackers could change some data, but it’s limited—not everything goes. Availability (A:H) Could take the service down hard or make it unusable for people who depend on it.	2.2	4.2	[email protected]
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

6.5

3.1

MEDIUM

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/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: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: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:N): Doesn’t really leak secrets in a meaningful way.
Integrity (I:L): Attackers could change some data, but it’s limited—not everything goes.
Availability (A:H): Could take the service down hard or make it unusable for people who depend on it.

2.2

4.2

[email protected]

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-2019-11049

vendor	priority	summary	link
`redhat`	medium	—	https://access.redhat.com/security/cve/CVE-2019-11049
`ubuntu`	medium	CVE-2019-11049 medium priority: Ubuntu including 4 source packages (php5, php7.0, php7.2, php7.3), 24 status rows across 6 suites (bionic, disco, eoan, trusty, upstream, xenial): DNE 15, not-affected 5, needs-triage 4.	https://ubuntu.com/security/CVE-2019-11049

Affected software / configurations for CVE-2019-11049

Vendor	Product	Version	Raw CPE
php	php	>= 7.3.0, <= 7.3.13	cpe:2.3:a:php:php::::::::
php	php	7.4.0	cpe:2.3:a:php:php:7.4.0:::::::*
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:::::::*
tenable	securitycenter	< 5.19.0	cpe:2.3:a:tenable:securitycenter::::::::

References for CVE-2019-11049

URL	Tags
https://bugs.php.net/bug.php?id=78943	Mailing List Patch Vendor Advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/N7GCOAE6KVHYJ3UQ4KLPLTGSLX6IRVRN/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/XWRQPYXVG43Q7DXMXH6UVWMKWGUW552F/
https://seclists.org/bugtraq/2020/Feb/27	Mailing List Third Party Advisory
https://security.netapp.com/advisory/ntap-20200103-0002/	Third Party Advisory
https://www.debian.org/security/2020/dsa-4626	Third Party Advisory
https://www.tenable.com/security/tns-2021-14	Third Party Advisory

URL

CVE-2019-11049 | mail() may release string with refcount==1 twice

Exploit prediction scoring system (EPSS) score for CVE-2019-11049

Common vulnerability scoring system (CVSS) metrics for CVE-2019-11049

Weakness enumeration for CVE-2019-11049

OS Trackers for CVE-2019-11049

Affected software / configurations for CVE-2019-11049

References for CVE-2019-11049