CVE-2019-9853 [High] | Security Bypass in Libreoffice

LibreOffice documents can contain macros. The execution of those macros is controlled by the document security settings, typically execution of macros are blocked by default. A URL decoding flaw existed in how the urls to the macros within the document were processed and categorized, resulting in the possibility to construct a document where macro execution bypassed the security settings. The documents were correctly detected as containing macros, and prompted the user to their existence within the documents, but macros within the document were subsequently not controlled by the security settings allowing arbitrary macro execution This issue affects: LibreOffice 6.2 series versions prior to 6.2.7; LibreOffice 6.3 series versions prior to 6.3.1.

#	Date	Old EPSS score	New EPSS score	Delta (New - Old)
1	2025-11-21	0.69%	0.29%	-0.40%
2	2025-11-18	0.29%	0.69%	+0.40%
3	2025-03-30	—	0.29%	—

Date

Old EPSS score

New EPSS score

Delta (New - Old)

2025-11-21

0.69%

0.29%

-0.40%

2025-11-18

0.29%

0.69%

+0.40%

2025-03-30

—

0.29%

—

Base score	Version	Severity	Vector	Exploitability	Impact	Score source
7.8	3.1	HIGH	`CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H` 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: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: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.	1.8	5.9	[email protected]
6.8	2.0	MEDIUM	`AV:N/AC:M/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: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:P) Partial integrity impact. Availability impact (A:P) Partial availability impact.	8.6	6.4	[email protected]

Base score

Version

Severity

Vector

Exploitability

Impact

Score source

7.8

3.1

HIGH

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

1.8

5.9

[email protected]

6.8

2.0

MEDIUM

AV:N/AC:M/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: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:P): Partial integrity impact.
Availability impact (A:P): Partial availability impact.

8.6

6.4

[email protected]

OS Trackers for CVE-2019-9853

vendor	priority	summary	link
`alpine`	high	CVE-2019-9853: 1 source package rows (libreoffice); 4 state rows across 2 repos (3.22-community, edge-community); fixed 0, open 4.	https://security.alpinelinux.org/vuln/CVE-2019-9853
`debian`	not yet assigned	CVE-2019-9853 not yet assigned priority: Debian including 1 source packages (libreoffice), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5.	https://security-tracker.debian.org/tracker/CVE-2019-9853
`redhat`	medium	—	https://access.redhat.com/security/cve/CVE-2019-9853
`suse`	medium	CVE-2019-9853 severity moderate: SUSE including 1483 source package names (bluez-5.13-5.20.6, bluez-cups-5.13-5.20.6, …), 3223 product×package rows across 41 product lines (SUSE Linux Enterprise Module for Basesystem 15, SUSE Linux Enterprise Module for Basesystem 15 SP1, … (41 product lines)): Fixed 2970, Known Not Affected 253.	https://www.suse.com/security/cve/CVE-2019-9853/
`ubuntu`	medium	CVE-2019-9853 medium priority: Ubuntu including 1 source packages (libreoffice), 5 status rows across 5 suites (bionic, disco, trusty, upstream, xenial): released 4, DNE 1.	https://ubuntu.com/security/CVE-2019-9853

Affected software / configurations for CVE-2019-9853

Vendor	Product	Version	Raw CPE
libreoffice	libreoffice	>= 6.2.0, < 6.2.6	cpe:2.3:a:libreoffice:libreoffice::::::::
libreoffice	libreoffice	>= 6.3.0, < 6.3.1	cpe:2.3:a:libreoffice:libreoffice::::::::

URL	Tags
http://lists.opensuse.org/opensuse-security-announce/2019-12/msg00040.html
http://packetstormsecurity.com/files/156474/Open-Xchange-App-Suite-Documents-Server-Side-Request-Forgery.html
http://seclists.org/fulldisclosure/2020/Feb/23
https://lists.apache.org/thread.html/19c917f7c8a0d8f62142046fabfe3e2c7d6091ef1f92b99c6e79e24e%40%3Ccommits.openoffice.apache.org%3E
https://lists.apache.org/thread.html/27339e8a9a1e9bb47fbdb939b338256d0356250a1974aaf4d774f683%40%3Ccommits.openoffice.apache.org%3E
https://lists.apache.org/thread.html/306a374361891eb17c6cffc99c3d7be1d3152a99c839d4231edc1631%40%3Ccommits.openoffice.apache.org%3E
https://lists.apache.org/thread.html/3a5570ca5cd14ad08e24684c71cfeff3a507f108fe3cf30ba4f58226%40%3Ccommits.openoffice.apache.org%3E
https://lists.apache.org/thread.html/4ae0e6e52600f408d943ded079d314733ce188b04b04471464f89c4f%40%3Ccommits.openoffice.apache.org%3E
https://lists.apache.org/thread.html/70da9481dca267405e1d79e53942264765ef3f55c9a563c3737e3926%40%3Ccommits.openoffice.apache.org%3E
https://lists.apache.org/thread.html/7394e6b5f78a878bd0c44e9bc9adf90b8cdf49e9adc0f287145aba9b%40%3Ccommits.openoffice.apache.org%3E
https://lists.apache.org/thread.html/9dc85d9937ad7f101047c53f78c00e8ceb135eaeff7dcf4724b46f2c%40%3Ccommits.openoffice.apache.org%3E
https://lists.apache.org/thread.html/a5231ad45b030b54828c7b0b62a7e7d4b48481c7cb83ff628e07fa43%40%3Ccommits.openoffice.apache.org%3E
https://lists.apache.org/thread.html/a540d1b6f9a7ebb206adba02839f654a6ee63a7b0976f559a847e49a%40%3Ccommits.openoffice.apache.org%3E
https://lists.apache.org/thread.html/ca216900abd846f0220fe18b95f9f787bdbe0e87fa4eee822073cd69%40%3Ccommits.openoffice.apache.org%3E
https://lists.debian.org/debian-lts-announce/2019/10/msg00005.html
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/KQGBRSD73KTDZ2MPAOL7FBWO3SQVYE5B/
https://www.libreoffice.org/about-us/security/advisories/CVE-2019-9853/	Vendor Advisory

URL

CVE-2019-9853 | Insufficient URL decoding flaw in categorizing macro location

Exploit prediction scoring system (EPSS) score for CVE-2019-9853

Common vulnerability scoring system (CVSS) metrics for CVE-2019-9853

Weakness enumeration for CVE-2019-9853

OS Trackers for CVE-2019-9853

Affected software / configurations for CVE-2019-9853

References for CVE-2019-9853