CVE-2019-17263: In libyal libfwsi before 20191006, libfwsi_extension_block_copy_from_byte_stream in libfwsi_extension_block.c

Q: How do I fix CVE-2019-17263?

libfwsi: upgrade to 20191006. Exact commands for each OS are on this page.

Q: Is CVE-2019-17263 being exploited?

CVE-2019-17263 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2019-17263 affect?

CVE-2019-17263 affects libfwsi. Severity is low (CVSS 3.3). In libyal libfwsi before 20191006, libfwsi_extension_block_copy_from_byte_stream in libfwsi_extension_block.c has a heap-based buffer over-read because rejection of an unsupported size only considers values less than 6, even though values o

Q: How urgent is CVE-2019-17263?

Priority 28/100. Public exploit reference

Routine

LOW 3.3UPGRADE

CVE-2019-17263 is a low-severity flaw (CVSS 3.3) affecting libfwsi. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

In libyal libfwsi before 20191006, libfwsi_extension_block_copy_from_byte_stream in libfwsi_extension_block.c has a heap-based buffer over-read because rejection of an unsupported size only considers values less than 6, even though values of 6 and 7 are also unsupported. NOTE: the vendor has disputed this as described in the GitHub issue

Why this priority

Public exploit reference

A fixed release or distro patch exists.

Risk facts

CVSS score	3.3 (Low)
Attack vector	Local
Attack complexity	Low
Privileges needed	Low
User interaction	None
EPSS exploit chance	0.5% (top 55%)
CISA exploited list	No
Weakness	CWE-125
Published	2019-10-06
Last modified	2026-06-17

Publisher (CNA): MITRE · Vendor: libfwsi project

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2019-10-06 22:15 UTCPublished CVE record published
2026-06-17 02:23 UTCUpdated Record last modified

libfwsi project libfwsi UPGRADE

Affected: < 20191006

Fixed in: 20191006

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy libfwsi || rpm -q libfwsi || libfwsi --version

2. UPGRADE to 20191006 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade libfwsi

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade libfwsi

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2019-17263?

libfwsi: upgrade to 20191006. Exact commands for each OS are on this page.

Is CVE-2019-17263 being exploited?

CVE-2019-17263 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2019-17263 affect?

CVE-2019-17263 affects libfwsi. Severity is low (CVSS 3.3). In libyal libfwsi before 20191006, libfwsi_extension_block_copy_from_byte_stream in libfwsi_extension_block.c has a heap-based buffer over-read because rejection of an unsupported size only considers values less than 6, even though values o

How urgent is CVE-2019-17263?

Priority 28/100. Public exploit reference

Software pages

GitHub vulnerabilities

References

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