VulnerabilityPublished 2 Jun 2025

CVE-2025-29785: quic-go · Uncaught Exception

Affects quic-goSource CVE Database V5

Not known to be exploited · CVSS 7.5 High · fixed in 0.50.1 : patch quic-go soon.

Data as of 26 Oct 2026, 10:12 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.
Patch: Available – fixed in 0.50.1

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 2 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 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
Gogithub.com/quic-go/quic-go`pkg:golang/github.com/quic-go/quic-go`Other threats	Affected =0.50.0	Fixed in–

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AI-suggested

European organizations should immediately identify any deployments of quic-go version 0.50.0 within their infrastructure, including embedded systems, microservices, and cloud-native applications. The primary mitigation is to upgrade to quic-go version 0.50.1 or later, which contains the patch addressing this vulnerability. Since no workarounds exist, patching is critical. Organizations should also implement network-level protections such as rate limiting and anomaly detection to identify unusual patterns of QUIC traffic, especially from multiple remote addresses that could indicate attempts to trigger path validation logic. Monitoring logs for unexpected crashes or exceptions in services using quic-go can help detect exploitation attempts. Additionally, applying strict ingress filtering and employing Web Application Firewalls (WAFs) capable of inspecting QUIC traffic may reduce exposure. For critical services, consider deploying redundancy and failover mechanisms to mitigate potential downtime caused by exploitation attempts.

Description

quic-go is an implementation of the QUIC protocol in Go. The loss recovery logic for path probe packets that was added in the v0.50.0 release can be used to trigger a nil-pointer dereference by a malicious QUIC client. In order to do so, the attacker first sends valid QUIC packets from different remote addresses (thereby triggering the newly added path validation logic: the server sends path probe packets), and then sending ACKs for packets received from the server specifically crafted to trigger the nil-pointer dereference.v0.50.1 contains a patch that fixes the vulnerability. This release contains a test that generates random sequences of sent packets (both regular and path probe packets), that was used to verify that the patch actually covers all corner cases. No known workarounds are available.

Impact

For European organizations, this vulnerability poses a significant risk primarily to services and applications that utilize quic-go version 0.50.0 for QUIC protocol communication. Since QUIC is increasingly used to improve web performance and security, particularly in HTTP/3 implementations, affected servers could be forced into denial of service by remote attackers, leading to service outages and degraded user experience. This can impact critical web services, APIs, and real-time communication platforms relying on quic-go. The availability disruption could affect e-commerce, financial services, healthcare, and government portals, potentially causing operational downtime and reputational damage. Given the lack of known workarounds, organizations must prioritize patching. The vulnerability does not directly expose data confidentiality or integrity but can be leveraged as part of a broader attack strategy to disrupt services or as a vector for further exploitation if combined with other vulnerabilities.

References

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 9 Jul 2025, 12:56 UTC

WeaknessesCWE-248

Technical details

References

Community reviews

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