CVE-2026-54890Public exploitNetwork attack vector

VM crash via BIT_BINARY_EXT size underflow

Published Jul 27, 2026 · Updated Jul 27, 2026

Denial of service in Erlang/OTP allows remote attackers to crash the BEAM VM by supplying crafted External Term Format data. In erts/emulator/beam/external.c, the BIT_BINARY_EXT decoder accepts zero length and zero trailing bits, underflows the unsigned bit-size calculation, and requests an enormous allocation. Reachability requires an application or distribution node to decode attacker-controlled ETF; exploitation aborts the VM rather than raising an Erlang exception.

CVSS severity8.2
High
EPSS probability0.42%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Denial of service in Erlang/OTP allows remote attackers to crash the BEAM VM by supplying crafted External Term Format data. In erts/emulator/beam/external.c, the BIT_BINARY_EXT decoder accepts zero length and zero trailing bits, underflows the unsigned bit-size calculation, and requests an enormous allocation. Reachability requires an application or distribution node to decode attacker-controlled ETF; exploitation aborts the VM rather than raising an Erlang exception.

The record

CVE
CVE-2026-54890
Published
Jul 27, 2026
Updated
Jul 27, 2026
Vendor
Erlang
Product
Erlang/OTP
Classifications
CWE-789, CWE-191, CWE-1284, CAPEC-92, CAPEC-130, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jul 27, 2026CVE publishedPublication date reported by the CVE source.
  2. Jul 27, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=15.0 <* changes=[{"at":"15.2.7.11","status":"unaffected"},{"at":"16.4.0.4","status":"unaffected"},{"at":"17.0.4","status":"unaffected"}]
  2. Affected versionversion=24ef4cbaeda9b9c26682cba75f2f15b0c58722aa <dc1bf9344c0ce62717cf60866590cea0242780fd
  3. Affected versionversion=27.0 <* changes=[{"at":"27.3.4.15","status":"unaffected"},{"at":"28.5.0.4","status":"unaffected"},{"at":"29.0.4","status":"unaffected"}]

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Erlang · Erlang/OTPversion=15.0 <* changes=[{"at":"15.2.7.11","status":"unaffected"},{"at":"16.4.0.4","status":"unaffected"},{"at":"17.0.4","status":"unaffected"}]; version=24ef4cbaeda9b9c26682cba75f2f15b0c58722aa <dc1bf9344c0ce62717cf60866590cea0242780fd; version=27.0 <* changes=[{"at":"27.3.4.15","status":"unaffected"},{"at":"28.5.0.4","status":"unaffected"},{"at":"29.0.4","status":"unaffected"}]

Published CVSS scores

7.5NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
8.2Erlang Ecosystem FoundationCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
7.5Red HatCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-789Memory Allocation with Excessive Size Value
CWE-191Integer Underflow (Wrap or Wraparound)
CWE-1284Improper Validation of Specified Quantity in Input
CAPEC-92Forced Integer Overflow
CAPEC-130Excessive Allocation
T1499.004Application or System Exploitation

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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