CVE-2026-4988: A security flaw has been discovered in Open5GS 2.7.6

This week

LOW 3.7REMOTEDOWNGRADE

CVE-2026-4988 is a low-severity flaw (CVSS 3.7) affecting open5gs. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

A security flaw has been discovered in Open5GS 2.7.6. This issue affects the function smf_gx_cca_cb/smf_gy_cca_cb/smf_s6b of the component CCA Message Handler. The manipulation results in denial of service. The attack may be launched remotely. Attacks of this nature are highly complex. The exploitability is assessed as difficult. The exploit has been released to the public and may be used for attacks.

Why this priority

Public exploit reference
Remotely exploitable, no login, no user action

No fix is published yet: follow the downgrade or mitigation steps.

Risk facts

CVSS score	3.7 (Low)
Attack vector	Network (remote)
Attack complexity	High
Privileges needed	None
User interaction	None
EPSS exploit chance	0.6% (top 53%)
CISA exploited list	No
Weakness	CWE-404
Published	2026-03-27
Last modified	2026-06-17

Publisher (CNA): VulDB · Vendor: open5gs

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-03-27 22:16 UTCPublished CVE record published
2026-06-17 10:57 UTCUpdated Record last modified

open5gs open5gs DOWNGRADE

Affected: 2.7.6

Fixed in: no fixed release known

Safe to downgrade to: a release before 2.7.6

1. Check installed version

apt-cache policy open5gs || rpm -q open5gs || open5gs --version

2. No fixed release: DOWNGRADE to a release before 2.7.6 (Debian / Ubuntu)

apt-cache madison open5gs sudo apt install open5gs=<VERSION_BEFORE_2.7.6> sudo apt-mark hold open5gs

2. No fixed release: DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list open5gs sudo dnf downgrade open5gs-<VERSION_BEFORE_2.7.6> sudo dnf versionlock add open5gs

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-4988?

open5gs: downgrade or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2026-4988 being exploited?

CVE-2026-4988 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-4988 affect?

CVE-2026-4988 affects open5gs. Severity is low (CVSS 3.7). A security flaw has been discovered in Open5GS 2.7.6. This issue affects the function smf_gx_cca_cb/smf_gy_cca_cb/smf_s6b of the component CCA Message Handler. The manipulation results in denial of service. The attack may be launched remote

How urgent is CVE-2026-4988?

Priority 35/100. Public exploit reference; Remotely exploitable, no login, no user action

Related CVEs

CVE-2026-8743 MEDIUM 6.3 UPGRADE A vulnerability was found in Open5GS up to 2.7.6
CVE-2026-8187 MEDIUM 5.3 UPGRADE A flaw has been found in Open5GS up to 2.7.7
CVE-2026-8186 MEDIUM 5.3 UPGRADE A vulnerability was detected in Open5GS up to 2.7.7
CVE-2026-8252 MEDIUM 4.3 UPGRADE A vulnerability was determined in Open5GS up to 2.7.7
CVE-2026-8266 MEDIUM 4.3 UPGRADE A vulnerability was detected in Open5GS up to 2.7.7

References

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