CVE-2025-59777VulnerabilityPublished 10 Nov 2025

CVE-2025-59777: GNU libbmicrohttpd · NULL pointer dereference

Affects GNU libbmicrohttpdSource CVE Database V5

Not known to be exploited · CVSS 7.5 High.

Data as of 25 Oct 2026, 19:02 UTC

CVSS 3.0 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:3.0/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 10 Nov 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
GNU Project GNU libbmicrohttpd	Affected >1.0.2	Fixed in–

AI-suggested

European organizations should immediately inventory all systems and applications that use GNU libmicrohttpd, focusing on versions 1.0.2 and earlier. They should upgrade to the latest patched version of libmicrohttpd that includes the fix from commit ff13abc or later. Where upgrading is not immediately feasible, organizations should implement network-level protections such as firewall rules or intrusion prevention systems (IPS) to detect and block malformed packets targeting libmicrohttpd. Monitoring network traffic for unusual HTTP requests or crashes in services using libmicrohttpd can provide early detection of exploitation attempts. Additionally, applying strict input validation and rate limiting on HTTP endpoints can reduce the risk of triggering the vulnerability. For embedded devices, coordinate with vendors to obtain firmware updates or patches. Finally, incorporate this vulnerability into incident response plans to quickly address any DoS incidents caused by exploitation.

Description

NULL pointer dereference vulnerability exists in GNU libmicrohttpd v1.0.2 and earlier. The vulnerability was fixed in commit ff13abc on the master branch of the libmicrohttpd Git repository, after the v1.0.2 tag. A specially crafted packet sent by an attacker could cause a denial-of-service (DoS) condition.

Impact

For European organizations, the primary impact of CVE-2025-59777 is service disruption due to denial-of-service conditions in applications or devices using vulnerable versions of libmicrohttpd. This can affect embedded devices, network appliances, or software components that rely on libmicrohttpd for HTTP server functionality. Critical infrastructure sectors such as telecommunications, energy, and manufacturing that deploy embedded systems with this library may experience outages or degraded service availability. The lack of confidentiality or integrity impact limits data breach risks, but operational continuity could be compromised. Disruption of services could lead to financial losses, reputational damage, and potential regulatory scrutiny under frameworks like GDPR if service availability is critical to compliance. The remote and unauthenticated nature of the exploit increases the risk of widespread attacks, especially if automated scanning tools identify vulnerable systems. Organizations with large deployments of GNU software or embedded Linux-based devices are particularly vulnerable.

References

Community reviews

Loading reviews…

Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 17 Nov 2025, 04:46 UTC

Technical details

References

Community reviews

Related threats