VulnerabilityPublished 20 Jan 2026Updated 22 Jan 2026

CVE-2025-15281: 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, 14:05 UTC

CVSS 3.1 base score

7.5High

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

EPSS: 0.4% chance of exploitation in 30 days – higher than 41% 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:N/I:N/A:H

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

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: None: There is no loss of confidentiality within the impacted component.
Integrity: None: There is no loss of integrity within the impacted component.
Availability: High: There is total loss of availability, resulting in the attacker being able to fully deny access to resources in the impacted component; this loss is either sustained (while the attacker continues to deliver the attack) or persistent (the condition persists even after the attack has completed). Alternatively, the attacker has the ability to deny some availability, but the loss of availability presents a direct, serious consequence to the impacted component (e.g., the attacker cannot disrupt existing connections, but can prevent new connections; the attacker can repeatedly exploit a vulnerability that, in each instance of a successful attack, leaks a only small amount of memory, but after repeated exploitation causes a service to become completely unavailable).

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 20 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 or the CVSS exploit maturity 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

Monitor official GNU C Library (glibc) repositories and security advisories for patches addressing CVE-2025-15281 and apply updates promptly once available.
In the interim, audit applications and scripts to identify usage of the wordexp function with WRDE_REUSE and WRDE_APPEND flags; avoid or refactor such calls where possible to prevent triggering the vulnerability.
Employ runtime monitoring and logging to detect abnormal process terminations or crashes related to wordfree calls, enabling early detection of exploitation attempts.
Harden Linux systems by restricting network exposure of services that might invoke vulnerable glibc functions, using firewalls and network segmentation.
Use containerization or sandboxing to isolate critical applications, limiting the impact of potential process aborts.
Conduct thorough testing of updated glibc versions in staging environments before deployment to ensure compatibility and stability.
Engage with Linux distribution vendors for backported patches if upgrading glibc to a newer major version is not immediately feasible.
Educate development and operations teams about the vulnerability to raise awareness and encourage secure coding practices avoiding uninitialized resource usage.

Description

Calling wordexp with WRDE_REUSE in conjunction with WRDE_APPEND in the GNU C Library version 2.0 to version 2.42 may cause the interface to return uninitialized memory in the we_wordv member, which on subsequent calls to wordfree may abort the process.

Impact

The primary impact of CVE-2025-15281 is denial of service due to process aborts triggered by the use of uninitialized memory in glibc's wordexp function. For European organizations, this can translate into unexpected crashes of critical applications or services that depend on glibc, particularly those that utilize wordexp with the affected flags. This could disrupt web servers, database systems, or other backend services running on Linux distributions shipping with vulnerable glibc versions. Since glibc is a fundamental component in most Linux-based systems, the scope of affected systems is broad, potentially impacting enterprise servers, cloud infrastructure, and embedded systems. The vulnerability does not compromise confidentiality or integrity, so data breaches or unauthorized data modification are not direct concerns. However, availability disruptions can have cascading effects, especially in sectors like finance, healthcare, telecommunications, and government services, where uptime is critical. The ease of exploitation (no privileges or user interaction needed) increases the risk of automated attacks or exploitation by malicious actors scanning for vulnerable systems. European organizations with large-scale Linux deployments or those running legacy systems with outdated glibc versions are at higher risk. The lack of known exploits in the wild currently reduces immediate threat but does not eliminate future exploitation risks.

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

Community reviews

Loading reviews…

Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 27 Jan 2026, 19:52 UTC

WeaknessesCWE-908

Technical details

References

Community reviews

Related threats