VulnerabilityPublished 15 Jan 2026Updated 20 Jan 2026

CVE-2026-0915: The GNU C Library glibc · Use of Uninitialized Resource

Affects The GNU C Library glibcSource CVE Database V5

Not known to be exploited · CVSS 7.5 High.

Data as of 26 Oct 2026, 09:16 UTC

CVSS 3.1 base score

7.5High

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 0.6% chance of exploitation in 30 days – higher than 49% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

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

Attack Vector: Network
Attack Complexity: Low
Privileges Required: None
User Interaction: None
Scope: Unchanged
Confidentiality: High
Integrity: None
Availability: None

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: High: There is total loss of confidentiality, resulting in all resources within the impacted component being divulged to the attacker. Alternatively, access to only some restricted information is obtained, but the disclosed information presents a direct, serious impact.
Integrity: None: There is no loss of integrity within the impacted component.
Availability: None: There is no impact to availability within the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 15 Jan 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Affected software

Product	Affected	Fixed in
The GNU C Libraryglibc	Affected >=2.0 <=2.42	Fixed in–
Debiandebian/glibc`pkg:deb/debian/glibc`Other threats	Affected =2.0	Fixed in–

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

1. Immediately review and audit the nsswitch.conf configuration on all affected systems to identify and modify entries that specify the DNS backend for network queries, especially those involving getnetbyaddr or getnetbyaddr_r calls. 2. Where possible, temporarily disable or restrict the use of the DNS backend for network name resolution until patches are available. 3. Monitor DNS resolver traffic for unusual or unexpected queries that may indicate exploitation attempts or data leakage. 4. Implement network-level controls such as DNS query filtering and logging to detect anomalous patterns. 5. Apply patches or updates from the GNU C Library project as soon as they are released to address this vulnerability. 6. Conduct internal penetration testing and code audits to identify any indirect exposure resulting from this vulnerability. 7. Educate system administrators and security teams about the specific conditions that trigger the vulnerability to ensure rapid detection and response. 8. Consider deploying runtime memory protection tools or stack canaries that may help detect exploitation attempts involving uninitialized memory usage.

Description

Calling getnetbyaddr or getnetbyaddr_r with a configured nsswitch.conf that specifies the library's DNS backend for networks and queries for a zero-valued network in the GNU C Library version 2.0 to version 2.42 can leak stack contents to the configured DNS resolver.

Impact

For European organizations, the confidentiality breach posed by CVE-2026-0915 could lead to exposure of sensitive internal data, including credentials, cryptographic keys, or other critical information residing in stack memory. This is particularly concerning for sectors such as finance, healthcare, telecommunications, and government, where data privacy and security are paramount. The vulnerability could be exploited remotely, increasing the attack surface for organizations with externally facing services that rely on glibc for network name resolution. While the vulnerability does not directly compromise system integrity or availability, the leaked information could facilitate further attacks, including lateral movement or privilege escalation. The impact is amplified in environments where DNS queries are logged or monitored, as attackers might intercept or analyze DNS traffic to extract leaked data. Given the extensive deployment of Linux-based systems across European enterprises and public sector infrastructure, the potential for widespread data leakage is significant if unmitigated.

CWE-908Use of Uninitialized Resource (opens in a new tab)
Base weaknessLikelihood of exploit: Medium
The product uses or accesses a resource that has not been initialized.
Implementation
Explicitly initialize the resource before use. If this is performed through an API function or standard procedure, follow all required steps.
Implementation
Pay close attention to complex conditionals that affect initialization, since some branches might not perform the initialization.
Implementation
Avoid race conditions (CWE-362) during initialization routines.
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 23 Jan 2026, 19:50 UTC

WeaknessesCWE-908

Technical details

References

Community reviews

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