CVE-2020-28928

In musl libc through 1.2.1, wcsnrtombs mishandles particular combinations of destination buffer...

5.5 MediumFix available

In musl libc through 1.2.1, wcsnrtombs mishandles particular combinations of destination buffer size and source character limit, as demonstrated by an invalid write access (buffer overflow).

Attack profile

How easy it is to exploit

Attack vector: Local
Complexity: Low
Privileges needed: Low
User interaction: None

What an attacker can affect

Confidentiality: None
Integrity: None
Availability: High

Exploit likelihood

0.65%Down 0.2 points since Apr 14, 2021

What each source reports

NVD Score used 5.5

In musl libc through 1.2.1, wcsnrtombs mishandles particular combinations of destination buffer size and source character limit, as demonstrated by an invalid write access (buffer overflow).

Record: CVE-2020-28928
CVSS 3.1: 5.5 MediumCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
CVSS 2.0: 2.1 LowAV:L/AC:L/Au:N/C:N/I:N/A:P
Weakness: CWE-787
Updated: 2026-11-02

CVE List No score

In musl libc through 1.2.1, wcsnrtombs mishandles particular combinations of destination buffer size and source character limit, as demonstrated by an invalid write access (buffer overflow).

Record: CVE-2020-28928
Updated: 2026-11-02

EUVDEUVD-2020-21316 No score

In musl libc through 1.2.1, wcsnrtombs mishandles particular combinations of destination buffer size and source character limit, as demonstrated by an invalid write access (buffer overflow).

Record: EUVD-2020-21316
Updated: 2026-11-03

GitHub AdvisoriesGHSA-7gwx-j9qc-6c6w No score

In musl libc through 1.2.1, wcsnrtombs mishandles particular combinations of destination buffer...

In musl libc through 1.2.1, wcsnrtombs mishandles particular combinations of destination buffer size and source character limit, as demonstrated by an invalid write access (buffer overflow).

Record: GHSA-7gwx-j9qc-6c6w
Weakness: CWE-787
Updated: 2026-11-02

OSVALPINE-CVE-2020-28928 5.5

In musl libc through 1.2.1, wcsnrtombs mishandles particular combinations of destination buffer size and source character limit, as demonstrated by an invalid write access (buffer overflow).

Record: ALPINE-CVE-2020-28928
CVSS 3.1: 5.5 MediumCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Updated: 2026-11-02

OSVBELL-CVE-2020-28928 5.5

CVE-2020-28928 does not affect BellSoft software

Record: BELL-CVE-2020-28928
CVSS 3.1: 5.5 MediumCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Updated: 2026-11-02

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OSV 5.5

In musl libc through 1.2.1, wcsnrtombs mishandles particular combinations of destination buffer size and source character limit, as demonstrated by an invalid write access (buffer overflow).

Record: CVE-2020-28928
CVSS 3.1: 5.5 MediumCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Updated: 2026-11-02

OSVDEBIAN-CVE-2020-28928 5.5

In musl libc through 1.2.1, wcsnrtombs mishandles particular combinations of destination buffer size and source character limit, as demonstrated by an invalid write access (buffer overflow).

Record: DEBIAN-CVE-2020-28928
CVSS 3.1: 5.5 MediumCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Updated: 2026-11-02

OSVUBUNTU-CVE-2020-28928 5.5

In musl libc through 1.2.1, wcsnrtombs mishandles particular combinations of destination buffer size and source character limit, as demonstrated by an invalid write access (buffer overflow).

Record: UBUNTU-CVE-2020-28928
CVSS 3.1: 5.5 MediumCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Updated: 2026-11-02

OSVUSN-5990-1 No score

musl vulnerabilities

It was discovered that musl did not handle certain i386 math functions properly. An attacker could use this vulnerability to cause a denial of service (crash) or possibly execute arbitrary code. This issue only affected Ubuntu 14.04 ESM, Ubuntu 16.04 ESM, and Ubuntu 18.04 LTS. (CVE-2019-14697)

It was discovered that musl did not handle wide-character conversion properly. A remote attacker could use this vulnerability to cause resource consumption (infinite loop), denial of service, or possibly execute arbitrary code. This issue only affected Ubuntu 14.04 ESM, Ubuntu 16.04 ESM, Ubuntu 18.04 LTS, and Ubuntu 20.04 LTS. (CVE-2020-28928)

Record: USN-5990-1
Updated: 2026-11-02

Affected products

Affected packages

Affected packages
Package	Affected	Fixed
`musl` Alpine:v3.10	before 1.1.22-r4	1.1.22-r4
`musl` Alpine:v3.11	before 1.1.24-r3	1.1.24-r3
`musl` Alpine:v3.12	before 1.1.24-r10	1.1.24-r10
`musl` Alpine:v3.13	before 1.2.2_pre2-r0	1.2.2_pre2-r0
`musl` Alpine:v3.14	before 1.2.2_pre2-r0	1.2.2_pre2-r0
`musl` Alpine:v3.15	before 1.2.2_pre2-r0	1.2.2_pre2-r0
`musl` Alpine:v3.16	before 1.2.2_pre2-r0	1.2.2_pre2-r0
`musl` Alpine:v3.17	before 1.2.2_pre2-r0	1.2.2_pre2-r0
`musl` Alpine:v3.18	before 1.2.2_pre2-r0	1.2.2_pre2-r0
`musl` Alpine:v3.19	before 1.2.2_pre2-r0	1.2.2_pre2-r0

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Affected packages
Package	Affected	Fixed
`musl` Alpine:v3.20	before 1.2.2_pre2-r0	1.2.2_pre2-r0
`musl` Alpine:v3.21	before 1.2.2_pre2-r0	1.2.2_pre2-r0
`musl` Alpine:v3.22	before 1.2.2_pre2-r0	1.2.2_pre2-r0
`musl` Alpine:v3.23	before 1.2.2_pre2-r0	1.2.2_pre2-r0
`musl` Alpine:v3.24	before 1.2.2_pre2-r0	1.2.2_pre2-r0
`musl` Alpine:v3.9	before 1.1.20-r6	1.1.20-r6
`musl` Debian:12	before 1.2.2-1	1.2.2-1
`musl` Debian:13	before 1.2.2-1	1.2.2-1
`musl` Debian:14	before 1.2.2-1	1.2.2-1
`musl` Debian:9	before 1.1.16-3+deb9u1, plus listed versions 1.1.16-3	1.1.16-3+deb9u1
`musl` Ubuntu:Pro:14.04:LTS	before 0.9.15-1ubuntu0.1~esm2, plus listed versions 0.9.14-20.9.14-2ubuntu10.9.15-10.9.15-1ubuntu0.1~esm1	0.9.15-1ubuntu0.1~esm2
`musl` Ubuntu:Pro:16.04:LTS	before 1.1.9-1ubuntu0.1~esm3, plus listed versions 1.1.9-11.1.9-1ubuntu0.1~esm2	1.1.9-1ubuntu0.1~esm3
`musl` Ubuntu:Pro:18.04:LTS	before 1.1.19-1ubuntu0.1~esm1, plus listed versions 1.1.16-31.1.18-11.1.19-1	1.1.19-1ubuntu0.1~esm1
`musl` Ubuntu:Pro:20.04:LTS	before 1.1.24-1ubuntu0.1~esm1, plus listed versions 1.1.23-2build11.1.24-1	1.1.24-1ubuntu0.1~esm1
`musl` Ubuntu:Pro:14.04:LTS From an advisory covering 2 CVEs	before 0.9.15-1ubuntu0.1~esm2, plus listed versions 0.9.14-20.9.14-2ubuntu10.9.15-10.9.15-1ubuntu0.1~esm1	0.9.15-1ubuntu0.1~esm2
`musl` Ubuntu:Pro:16.04:LTS From an advisory covering 2 CVEs	before 1.1.9-1ubuntu0.1~esm3, plus listed versions 1.1.9-11.1.9-1ubuntu0.1~esm2	1.1.9-1ubuntu0.1~esm3
`musl` Ubuntu:Pro:18.04:LTS From an advisory covering 2 CVEs	before 1.1.19-1ubuntu0.1~esm1, plus listed versions 1.1.16-31.1.18-11.1.19-1	1.1.19-1ubuntu0.1~esm1
`musl` Ubuntu:Pro:20.04:LTS From an advisory covering 2 CVEs	before 1.1.24-1ubuntu0.1~esm1, plus listed versions 1.1.23-2build11.1.24-1	1.1.24-1ubuntu0.1~esm1

History

History
Recorded	Changed	Sources
Nov 6, 2026	affected, facts
Nov 3, 2026	aliases	EUVD
Nov 2, 2026	first indexed	CVE List, GitHub Advisories, NVD, OSV

Dates are when Every CVE recorded each change. Upstream dates may differ.

In short

CVE-2020-28928 is a medium vulnerability (CVSS 5.5) in Musl-libc Musl, published November 24, 2020. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.65%, the 51st percentile. Fixed in musl 1.1.22-r4.

References

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