CVE-2026-70405 Erlang CVE debrief

Who should care

Defenders responsible for Erlang/OTP systems, particularly those exposed to untrusted networks, should assess exposure and prioritize patching. This includes operators, platform administrators, vulnerability management teams, and security teams who need to verify and apply patches for affected versions.

Why it matters

CVE-2026-70405 is a medium-severity vulnerability in Erlang/OTP snmp that can lead to denial-of-service attacks. Defenders should prioritize verifying and applying patches for affected versions.

• Degradation of availability due to large BER INTEGER length fields
• Potential for denial-of-service attacks
• Need for verification of affected versions and patch application

Technical summary

The Improper Validation of Specified Quantity in Input vulnerability in Erlang/OTP snmp allows a remote attacker to degrade availability by sending an SNMP message containing a BER INTEGER whose length field is arbitrarily large. This issue affects OTP from OTP 17.0 before OTP 27.3.4.17, from OTP 28.0 before OTP 28.5.0.6, and from OTP 29.0 before OTP 29.0.6. The decode runs before the PDU is processed, so no valid request is required beyond what the deployment demands to accept the message at all. Work grows superlinearly in the declared length because each operation acts on a progressively larger bignum.

Defensive priority

Defenders should prioritize verifying and applying patches for affected Erlang/OTP versions, particularly for systems exposed to untrusted networks.

Recommended defensive actions

• Verify and apply patches for affected Erlang/OTP versions
• Review and update SNMP configuration to limit exposure
• Monitor system performance and logs for potential attacks
• Review compensating controls for exposed systems while remediation is scheduled and verified
• Check relevant monitoring, detection, and logs for exposed assets that need extra review
• Track exceptions, retest remediated assets, and close the item only after evidence is documented
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up

Evidence notes

The CVE record and NVD entry provide details on the vulnerability, including its description and affected versions. The Improper Validation of Specified Quantity in Input vulnerability in Erlang/OTP snmp allows a remote attacker to degrade availability by sending an SNMP message containing a BER INTEGER whose length field is arbitrarily large. This issue affects OTP from OTP 17.0 before OTP 27.3.4.17, from OTP 28.0 before OTP 28.5.0.6, and from OTP 29.0 before OTP 29.0.6.

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.