CVE-2023-5156
Glibc: dos due to memory leak in getaddrinfo.c
A flaw was found in the GNU C Library. A recent fix for CVE-2023-4806 introduced the potential for a memory leak, which may result in an application crash.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- None
- Integrity
- None
- Availability
- High
Exploit likelihood
What each source reports
CVE List Score used
7.5
Glibc: dos due to memory leak in getaddrinfo.c
A flaw was found in the GNU C Library. A recent fix for CVE-2023-4806 introduced the potential for a memory leak, which may result in an application crash.
- Record
CVE-2023-5156- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-401
- Updated
- 2026-11-07
EUVDEUVD-2023-57494
7.5
A flaw was found in the GNU C Library. A recent fix for CVE-2023-4806 introduced the potential for a memory leak, which may result in an application crash.
- Record
EUVD-2023-57494- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-07
GitHub AdvisoriesGHSA-m7p3-g2hx-xfc3
3.7
A flaw was found in the GNU C Library. A recent fix for CVE-2023-4806 introduced the potential...
A flaw was found in the GNU C Library. A recent fix for CVE-2023-4806 introduced the potential for a memory leak, which may result in an application crash.
- Record
GHSA-m7p3-g2hx-xfc3- CVSS 3.1
- 3.7 Low
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L - Weakness
- CWE-401
- Updated
- 2026-11-02
NVD
7.5
A flaw was found in the GNU C Library. A recent fix for CVE-2023-4806 introduced the potential for a memory leak, which may result in an application crash.
- Record
CVE-2023-5156- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-401
- Updated
- 2026-11-07
OSVAZL-30046
7.5
CVE-2023-5156 affecting package glibc for versions less than 2.35-6
A flaw was found in the GNU C Library. A recent fix for CVE-2023-4806 introduced the potential for a memory leak, which may result in an application crash.
- Record
AZL-30046- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-02
OSVAZL-34734
7.5
CVE-2023-5156 affecting package glibc for versions less than 2.38-6
A flaw was found in the GNU C Library. A recent fix for CVE-2023-4806 introduced the potential for a memory leak, which may result in an application crash.
- Record
AZL-34734- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-05
Show 7 moreShow less
OSVBELL-CVE-2023-5156
7.5
- Record
BELL-CVE-2023-5156- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-02
OSV
7.5
Glibc: dos due to memory leak in getaddrinfo.c
A flaw was found in the GNU C Library. A recent fix for CVE-2023-4806 introduced the potential for a memory leak, which may result in an application crash.
- Record
CVE-2023-5156- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-401
- Updated
- 2026-11-02
OSVDEBIAN-CVE-2023-5156
7.5
A flaw was found in the GNU C Library. A recent fix for CVE-2023-4806 introduced the potential for a memory leak, which may result in an application crash.
- Record
DEBIAN-CVE-2023-5156- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-07
OSVOESA-2023-1688
7.5
glibc security update
The GNU C Library project provides the core libraries for the GNU system and GNU/Linux systems, as well as many other systems that use Linux as the kernel. These libraries provide critical APIs including ISO C11, POSIX.1-2008, BSD, OS-specific APIs and more. These APIs include such foundational facilities as open, read, write, malloc, printf, getaddrinfo, dlopen, pthread_create, crypt, login, exit and more.
Security Fix(es):
A flaw was found in glibc. In an extremely rare situation, the getaddrinfo function may access memory that has been freed, resulting in an application crash. This issue is only exploitable when a NSS module implements only the nss_gethostbyname2_r and nss_getcanonname_r hooks without implementing the nss*_gethostbyname3_r hook. The resolved name should return a large number of IPv6 and IPv4, and the call to the getaddrinfo function should have the AF_INET6 address family with AI_CANONNAME, AI_ALL and AI_V4MAPPED as flags.(CVE-2023-4806)
A flaw was found in glibc. In an uncommon situation, the gaih_inet function may use memory that has been freed, resulting in an application crash. This issue is only exploitable when the getaddrinfo function is called and the hosts database in /etc/nsswitch.conf is configured with SUCCESS=continue or SUCCESS=merge.(CVE-2023-4813)
A flaw was found in the GNU C Library. A recent fix for CVE-2023-4806 introduced the potential for a memory leak, which may result in an application crash.(CVE-2023-5156)
- Record
OESA-2023-1688- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-02
OSVUBUNTU-CVE-2023-5156
7.5
A flaw was found in the GNU C Library. A recent fix for CVE-2023-4806 introduced the potential for a memory leak, which may result in an application crash.
- Record
UBUNTU-CVE-2023-5156- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-02
OSVMGASA-2023-0281 No score
Updated glibc packages fix a security vulnerability
The updated packages fix a security vulnerability:
A flaw was found in the GNU C Library. A recent fix for CVE-2023-4806 introduced the potential for a memory leak, which may result in an application crash. (CVE-2023-5156)
- Record
MGASA-2023-0281- Updated
- 2026-11-02
OSVUSN-6541-1 No score
glibc vulnerabilities
It was discovered that the GNU C Library was not properly handling certain memory operations. An attacker could possibly use this issue to cause a denial of service (application crash). (CVE-2023-4806, CVE-2023-4813)
It was discovered that the GNU C library was not properly implementing a fix for CVE-2023-4806 in certain cases, which could lead to a memory leak. An attacker could possibly use this issue to cause a denial of service (application crash). This issue only affected Ubuntu 22.04 LTS and Ubuntu 23.04. (CVE-2023-5156)
- Record
USN-6541-1- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
glibcAzure Linux:2 |
before 2.35-6 | 2.35-6 |
glibcAzure Linux:3 |
before 2.38-6 | 2.38-6 |
glibcAlpaquita:23 |
2.37.0-r0 up to 2.37.0-r6 | 2.37.0-r6 |
glibcAlpaquita:stream |
2.37.0-r0 up to 2.37.0-r6 | 2.37.0-r6 |
glibcBellSoft Hardened Containers:23 |
2.37.0-r0 up to 2.37.0-r6 | 2.37.0-r6 |
glibcBellSoft Hardened Containers:stream |
2.37.0-r0 up to 2.37.0-r6 | 2.37.0-r6 |
glibcDebian:13 |
before 2.37-11 | 2.37-11 |
glibcDebian:14 |
before 2.37-11 | 2.37-11 |
glibcMageia:9 |
before 2.36-50.mga9 | 2.36-50.mga9 |
glibcopenEuler:20.03-LTS-SP1 From an advisory covering 3 CVEs |
before 2.28-97.oe1 | 2.28-97.oe1 |
Show 10 moreShow less
| Package | Affected | Fixed |
|---|---|---|
glibcopenEuler:20.03-LTS-SP3 From an advisory covering 3 CVEs |
before 2.28-97.oe1 | 2.28-97.oe1 |
glibcopenEuler:22.03-LTS From an advisory covering 3 CVEs |
before 2.34-136.oe2203sp2 | 2.34-136.oe2203sp2 |
glibcopenEuler:22.03-LTS-SP1 From an advisory covering 3 CVEs |
before 2.34-136.oe2203sp1 | 2.34-136.oe2203sp1 |
glibcopenEuler:22.03-LTS-SP2 From an advisory covering 3 CVEs |
before 2.34-136.oe2203sp2 | 2.34-136.oe2203sp2 |
eglibcUbuntu:Pro:14.04:LTS |
All versions, plus listed versions 2.17-93ubuntu42.18-0ubuntu12.18-0ubuntu22.18-0ubuntu42.18-0ubuntu5 Show 24 moreShow less2.18-0ubuntu62.18-0ubuntu72.19-0ubuntu22.19-0ubuntu32.19-0ubuntu42.19-0ubuntu52.19-0ubuntu62.19-0ubuntu6.12.19-0ubuntu6.32.19-0ubuntu6.42.19-0ubuntu6.52.19-0ubuntu6.62.19-0ubuntu6.72.19-0ubuntu6.82.19-0ubuntu6.92.19-0ubuntu6.102.19-0ubuntu6.112.19-0ubuntu6.132.19-0ubuntu6.142.19-0ubuntu6.152.19-0ubuntu6.15+esm12.19-0ubuntu6.15+esm22.19-0ubuntu6.15+esm32.19-0ubuntu6.15+esm4 |
None known |
glibcUbuntu:22.04:LTS |
before 2.35-0ubuntu3.5, plus listed versions 2.34-0ubuntu32.35-0ubuntu12.35-0ubuntu32.35-0ubuntu3.12.35-0ubuntu3.32.35-0ubuntu3.4 |
2.35-0ubuntu3.5 |
glibcUbuntu:Pro:16.04:LTS From an advisory covering 3 CVEs |
before 2.23-0ubuntu11.3+esm5, plus listed versions 2.21-0ubuntu42.21-0ubuntu52.21-0ubuntu62.23-0ubuntu12.23-0ubuntu2 Show 13 moreShow less2.23-0ubuntu32.23-0ubuntu42.23-0ubuntu52.23-0ubuntu62.23-0ubuntu72.23-0ubuntu92.23-0ubuntu102.23-0ubuntu112.23-0ubuntu11.22.23-0ubuntu11.32.23-0ubuntu11.3+esm12.23-0ubuntu11.3+esm22.23-0ubuntu11.3+esm3 |
2.23-0ubuntu11.3+esm5 |
glibcUbuntu:Pro:18.04:LTS From an advisory covering 3 CVEs |
before 2.27-3ubuntu1.6+esm1, plus listed versions 2.26-0ubuntu22.26-0ubuntu2.12.27-0ubuntu22.27-0ubuntu32.27-3ubuntu1 Show 5 moreShow less2.27-3ubuntu1.22.27-3ubuntu1.32.27-3ubuntu1.42.27-3ubuntu1.52.27-3ubuntu1.6 |
2.27-3ubuntu1.6+esm1 |
glibcUbuntu:20.04:LTS From an advisory covering 3 CVEs |
before 2.31-0ubuntu9.14, plus listed versions 2.30-0ubuntu22.30-0ubuntu32.31-0ubuntu52.31-0ubuntu62.31-0ubuntu7 Show 7 moreShow less2.31-0ubuntu92.31-0ubuntu9.12.31-0ubuntu9.22.31-0ubuntu9.32.31-0ubuntu9.72.31-0ubuntu9.92.31-0ubuntu9.12 |
2.31-0ubuntu9.14 |
glibcUbuntu:22.04:LTS From an advisory covering 3 CVEs |
before 2.35-0ubuntu3.5, plus listed versions 2.34-0ubuntu32.35-0ubuntu12.35-0ubuntu32.35-0ubuntu3.12.35-0ubuntu3.32.35-0ubuntu3.4 |
2.35-0ubuntu3.5 |
History
| Recorded | Changed | Sources |
|---|---|---|
| affected | ||
| facts | OSV | |
| first indexed | CVE List, EUVD, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2023-5156 is a high vulnerability (CVSS 7.5) in Gnu Glibc, published September 25, 2023. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 1.65%, the 76th percentile. Fixed in glibc 2.35-6.
References
access.redhat.com/security/cve/CVE-2023-5156
bugzilla.redhat.com/show_bug.cgi?id=2240541
sourceware.org/bugzilla/show_bug.cgi?id=30884
sourceware.org/git?p=glibc.git;a=commitdiff;h=ec6b95c3303c700eb89eebeda2d7264cc184a796
openwall.com/lists/oss-security/2023/10/03/4
openwall.com/lists/oss-security/2023/10/03/5
Show 24 moreShow less
openwall.com/lists/oss-security/2023/10/03/6
openwall.com/lists/oss-security/2023/10/03/8
security.gentoo.org/glsa/202402-01
cert-portal.siemens.com/productcert/html/ssa-831302.html
cert-portal.siemens.com/productcert/html/ssa-398330.html
nvd.nist.gov/vuln/detail/CVE-2023-5156
github.com/advisories/GHSA-m7p3-g2hx-xfc3
docs.bell-sw.com/security/cves/CVE-2023-5156
docs.bell-sw.com/security/advisories/BELL-SA-2023-2
access.redhat.com/downloads/content/package-browser
github.com/CVEProject/cvelistV5/tree/main/cves/2023/5xxx/CVE-2023-5156.json
security-tracker.debian.org/tracker/CVE-2023-5156
advisories.mageia.org/MGASA-2023-0281.html
bugs.mageia.org/show_bug.cgi?id=32328
cve.org/CVERecord?id=CVE-2023-5156
openeuler.org/en/security/safety-bulletin/detail.html?id=openEuler-SA-2023-1688
nvd.nist.gov/vuln/detail/CVE-2023-4806
nvd.nist.gov/vuln/detail/CVE-2023-4813
ubuntu.com/security/CVE-2023-5156
sourceware.org/pipermail/libc-alpha/2023-September/151691.html
ubuntu.com/security/notices/USN-6541-1
ubuntu.com/security/notices/USN-6541-2
ubuntu.com/security/CVE-2023-4806
ubuntu.com/security/CVE-2023-4813