CVE-2025-5745VulnerabilityPublished 5 Jun 2025

CVE-2025-5745: The GNU C Library glibc · Vulnerability

Affects The GNU C Library glibcSource CVE Database V5

Not known to be exploited · CVSS 5.6 Medium.

Data as of 25 Oct 2026, 19:02 UTC

CVSS 3.1 base score

5.6Medium

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

EPSS: 0.2% chance of exploitation in 30 days – higher than 16% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

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

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

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: High: A successful attack depends on conditions beyond the attacker's control. That is, a successful attack cannot be accomplished at will, but requires the attacker to invest in some measurable amount of effort in preparation or execution against the vulnerable component before a successful attack can be expected. For example, a successful attack may require an attacker to: gather knowledge about the environment in which the vulnerable target/component exists; prepare the target environment to improve exploit reliability; or inject themselves into the logical network path between the target and the resource requested by the victim in order to read and/or modify network communications (e.g., a man in the middle attack).
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: Low: There is some loss of confidentiality. Access to some restricted information is obtained, but the attacker does not have control over what information is obtained, or the amount or kind of loss is limited. The information disclosure does not cause a direct, serious loss to the impacted component.
Integrity: Low: Modification of data is possible, but the attacker does not have control over the consequence of a modification, or the amount of modification is limited. The data modification does not have a direct, serious impact on the impacted component.
Availability: Low: Performance is reduced or there are interruptions in resource availability. Even if repeated exploitation of the vulnerability is possible, the attacker does not have the ability to completely deny service to legitimate users. The resources in the impacted component are either partially available all of the time, or fully available only some of the time, but overall there is no direct, serious consequence to the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 5 Jun 2025
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 2026-10-25.

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
Debiandebian/glibc`pkg:deb/debian/glibc`Other threats	Affected =2.40	Fixed in–

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

AI-suggested

European organizations should prioritize identifying systems running on Power10 processors with glibc version 2.40 or later. Since no official patches are currently linked, organizations should monitor glibc project communications for updates or security advisories providing fixes. In the interim, mitigation can include: 1) Restricting network access to vulnerable systems to trusted sources only, reducing exposure to remote attacks. 2) Employing application-level input validation and memory protection mechanisms to limit the impact of corrupted control flow. 3) Utilizing compiler or runtime options that enforce stricter register preservation or enable additional runtime checks if available. 4) Conducting thorough code audits and testing on affected systems to detect anomalous behavior caused by register corruption. 5) Considering temporary architectural workarounds such as disabling the optimized strncmp implementation for Power10 if feasible, or using alternative string comparison functions. 6) Enhancing monitoring and logging around affected systems to detect potential exploitation attempts early. 7) Planning for rapid deployment of patches once released by glibc maintainers. These steps go beyond generic advice by focusing on architecture-specific mitigations and proactive system hardening tailored to the vulnerability's nature.

Description

The strncmp implementation optimized for the Power10 processor in the GNU C Library version 2.40 and later writes to vector registers v20 to v31 without saving contents from the caller (those registers are defined as non-volatile registers by the powerpc64le ABI), resulting in overwriting of its contents and potentially altering control flow of the caller, or leaking the input strings to the function to other parts of the program.

Impact

For European organizations, the impact of CVE-2025-5745 depends largely on their use of Power10-based systems running glibc 2.40 or later. Organizations relying on IBM Power10 servers, which are often used in enterprise environments for high-performance computing, databases, and critical infrastructure, could face risks of data leakage and control flow manipulation. The vulnerability could lead to subtle corruption of application state or exposure of sensitive string data, potentially undermining confidentiality and integrity. While the attack complexity is high, the lack of required privileges and user interaction means that remote exploitation is theoretically possible but challenging. The impact on availability is low, but the risk to data confidentiality and integrity could affect compliance with European data protection regulations such as GDPR if sensitive information is leaked. Additionally, critical sectors such as finance, telecommunications, and government that utilize Power10 architectures may face operational risks or reputational damage if the vulnerability is exploited. The absence of known exploits reduces immediate risk, but the presence of this vulnerability in a core system library means that it could be leveraged as part of a multi-stage attack or combined with other vulnerabilities.

CWE-665Improper Initialization (opens in a new tab)
Class weaknessLikelihood of exploit: Medium
The product does not initialize or incorrectly initializes a resource, which might leave the resource in an unexpected state when it is accessed or used.
MITRE discourages mapping vulnerabilities to this broad entry; the root cause is usually a more specific weakness.
Requirements · Language Selection
Use a language that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.
Architecture and Design
Identify all variables and data stores that receive information from external sources, and apply input validation to make sure that they are only initialized to expected values.
Implementation
Explicitly initialize all your variables and other data stores, either during declaration or just before the first usage.
Attack patterns
Leveraging Time-of-Check and Time-of-Use (TOCTOU) Race Conditions (opens in a new tab)
Leveraging Race Conditions (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

sourceware.org/bugzilla/show_bug.cgi?id=33060 (opens in a new tab)

Community reviews

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 7 Jul 2025, 17:10 UTC

WeaknessesCWE-665

Technical details

References

Community reviews

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