VulnerabilityPublished 2 Feb 2026Updated 6 Mar 2026

CVE-2026-1738: Open5GS · Reachable Assertion

Affects Open5GSSource CVE Database V5

Public exploit available · CVSS 6.9 Medium.

Data as of 26 Oct 2026, 17:16 UTC

CVSS 4.0 base score

6.9Medium

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

EPSS: 0.7% chance of exploitation in 30 days – higher than 54% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:P

Base metrics

Attack Vector: Network
Attack Complexity: Low
Attack Requirements: None
Privileges Required: None
User Interaction: None
Vulnerable system confidentiality: None
Vulnerable system integrity: None
Vulnerable system availability: Low
Subsequent system confidentiality: None
Subsequent system integrity: None
Subsequent system availability: None

Threat metrics

Exploit Maturity: POC

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

Attack Vector: Network: The vulnerable system is bound to the network stack and the set of possible attackers extends beyond the other options listed below, 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: The attacker must take no measurable action to exploit the vulnerability. The attack requires no target-specific circumvention to exploit the vulnerability. An attacker can expect repeatable success against the vulnerable system.
Attack Requirements: None: The successful attack does not depend on the deployment and execution conditions of the vulnerable system. The attacker can expect to be able to reach the vulnerability and execute the exploit under all or most instances of the vulnerability.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files of the vulnerable system to carry out an attack.
User Interaction: None: The vulnerable system can be exploited without interaction from any human user, other than the attacker.
Vulnerable system confidentiality: None: There is no loss of confidentiality within the Vulnerable System.
Vulnerable system integrity: None: There is no loss of integrity within the Vulnerable System.
Vulnerable system 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 Vulnerable System 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 Vulnerable System.
Subsequent system confidentiality: None: There is no loss of confidentiality within the Subsequent System or all confidentiality impact is constrained to the Vulnerable System.
Subsequent system integrity: None: There is no loss of integrity within the Subsequent System or all integrity impact is constrained to the Vulnerable System.
Subsequent system availability: None: There is no impact to availability within the Subsequent System or all availability impact is constrained to the Vulnerable System.
Exploit Maturity: POC: Based on threat intelligence sources each of the following must apply: · Proof-of-concept is publicly available · No knowledge of reported attempts to exploit this vulnerability · No knowledge of publicly available solutions used to simplify attempts to exploit the vulnerability

Definitions: FIRST CVSS v4.0 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 2 Feb 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: evidence found.
CVSS exploit maturity: proof of concept public
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), CVSS vector, 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
Open5GS	Affected 2.7.0 – 2.7.6 7 affected builds	Fixed in–
GitHubopen5gs/open5gs`pkg:github/open5gs/open5gs`Other threats	Affected 2.7.0 – 2.7.6 7 affected builds	Fixed in–

CPE configurations (1)

cpe:2.3:a:open5gs:open5gs:*:*:*:*:*:*:*:*

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AI-suggested

To mitigate CVE-2026-1738, organizations should immediately upgrade Open5GS to a version later than 2.7.6 where the vulnerability is fixed. If upgrading is not immediately feasible, applying any available patches or backported fixes from the Open5GS maintainers is critical. Network operators should implement strict network segmentation and firewall rules to restrict access to the SGWC interfaces, limiting exposure to untrusted networks. Monitoring and alerting for abnormal SGWC process crashes or assertion failures can help detect exploitation attempts early. Employing intrusion detection systems (IDS) with signatures for known exploit patterns can provide additional defense. Regularly auditing and updating 5G core network components and dependencies reduces exposure to known vulnerabilities. Finally, maintaining an incident response plan tailored to 5G infrastructure disruptions will help minimize downtime and impact if exploitation occurs.

Description

A flaw has been found in Open5GS up to 2.7.6. The impacted element is the function sgwc_tunnel_add of the file /src/sgwc/context.c of the component SGWC. Executing a manipulation of the argument pdr can lead to reachable assertion. The attack can be executed remotely. The exploit has been published and may be used. It is advisable to implement a patch to correct this issue. The issue report is flagged as already-fixed.

Impact

The primary impact of CVE-2026-1738 is on the availability of 5G core network services relying on Open5GS. Exploitation can cause assertion failures leading to crashes or denial of service in the SGWC component, disrupting packet routing and session continuity for mobile subscribers. This can degrade network performance, cause dropped connections, and impact user experience. For organizations operating 5G infrastructure, such disruptions can lead to service outages, financial losses, and reputational damage. Additionally, denial of service in core network elements can affect emergency communications and critical services relying on mobile connectivity. While the vulnerability does not directly compromise confidentiality or integrity, the availability impact alone is significant given the essential role of SGWC in 5G networks. The remote and unauthenticated nature of the exploit increases the risk of automated attacks or exploitation by malicious actors scanning for vulnerable systems.

References

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