CVE-2026-37229: FlexRIC v2.0.0 contains a reachable assertion in e2ap_create_pdu() triggered when ASN.1 PER decoding fails

This week

HIGH 7.5REMOTEDOWNGRADE

CVE-2026-37229 is a high-severity flaw (CVSS 7.5) affecting flexric. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

FlexRIC v2.0.0 contains a reachable assertion in e2ap_create_pdu() triggered when ASN.1 PER decoding fails. A remote unauthenticated attacker can send any non-PER byte sequence (e.g., a single 0x00 byte) over SCTP to the near-RT RIC (port 36421) or iApp (port 36422) to crash the process via SIGABRT. The assertion is reached before any protocol-level validation occurs. All three E2AP protocol versions (v1.01, v2.03, v3.01) are affected.

Why this priority

High severity
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	7.5 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.6% (top 50%)
CISA exploited list	No
Weakness	CWE-617
Published	2026-06-01
Last modified	2026-07-22

Publisher (CNA): MITRE · Vendor: mosaic5g

Last updated 2026-07-22 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-06-01 19:16 UTCPublished CVE record published
2026-07-22 07:10 UTCUpdated Record last modified

mosaic5g flexric DOWNGRADE

Affected: 2.0.0

Fixed in: no fixed release known

Safe to downgrade to: a release before 2.0.0

1. Check installed version

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

2. No fixed release: DOWNGRADE to a release before 2.0.0 (Debian / Ubuntu)

apt-cache madison flexric sudo apt install flexric=<VERSION_BEFORE_2.0.0> sudo apt-mark hold flexric

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

dnf --showduplicates list flexric sudo dnf downgrade flexric-<VERSION_BEFORE_2.0.0> sudo dnf versionlock add flexric

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-2026-37229?

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

Is CVE-2026-37229 being exploited?

CVE-2026-37229 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-2026-37229 affect?

CVE-2026-37229 affects flexric. Severity is high (CVSS 7.5). FlexRIC v2.0.0 contains a reachable assertion in e2ap_create_pdu() triggered when ASN.1 PER decoding fails. A remote unauthenticated attacker can send any non-PER byte sequence (e.g., a single 0x00 byte) over SCTP to the near-RT RIC (port 3

How urgent is CVE-2026-37229?

Priority 49/100. High severity; Public exploit reference; Remotely exploitable, no login, no user action

Related CVEs

CVE-2026-37234 HIGH 8.2 DOWNGRADE FlexRIC v2.0.0 allows a single SCTP connection to bind multiple xapp_ids by sending multiple E42_SETUP_REQUEST
CVE-2026-37226 HIGH 7.5 DOWNGRADE FlexRIC v2.0.0 crashes when the iApp receives an E42_RIC_SUBSCRIPTION_REQUEST referencing a non-existent E2 No
CVE-2026-37228 HIGH 7.5 DOWNGRADE FlexRIC v2.0.0 contains a reachable assertion in e2ap_recv_sctp_msg() (src/lib/ep/e2ap_ep.c)
CVE-2026-37230 HIGH 7.5 DOWNGRADE FlexRIC v2.0.0 crashes when the near-RT RIC receives a RIC_INDICATION message with a ran_func_id that does not
CVE-2026-37235 HIGH 7.5 DOWNGRADE FlexRIC v2.0.0 trusts the xapp_id field from E42 message payloads without binding it to the sender's SCTP asso

References

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