CVE-2026-55737

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Source
https://cve.org/CVERecord?id=CVE-2026-55737
Import Source
https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-55737.json
JSON Data
https://api.osv.dev/v1/vulns/CVE-2026-55737
Aliases
Downstream
Published
2026-07-27T15:13:54.699Z
Modified
2026-07-29T08:20:17.151079Z
Severity
  • 5.1 (Medium) CVSS_V4 - CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N CVSS Calculator
Summary
Heap pointer corruption via signed/unsigned mismatch in LARGE_TUPLE_EXT decoding in erts external term format decoder
Details

Signed to Unsigned Conversion Error and Out-of-bounds Write vulnerability in Erlang OTP erts allows an attacker who can supply a crafted Erlang external term format (ETF) binary to binarytoterm/1 to corrupt the BEAM heap pointer and crash the virtual machine.

When decoding a LARGETUPLEEXT term, the validation pass decodedsize() in erts/emulator/beam/external.c reads the 32-bit arity field as unsigned (getuint32()), while the decode pass decterm() reads the same field as a signed 32-bit integer (getint32()) into an int. An arity wire value of 0x80000000 passes validation as 2147483648 but decodes as -2147483648, so the subsequent hp += n moves the heap allocation pointer backward. Neither pass enforces the runtime tuple-arity limit MAX_ARITYVAL. The result is an out-of-bounds heap write; in practice the VM detects an impossible heap size and aborts, denying service. The required padding is large when uncompressed but the compressed-ETF envelope shrinks it to a small payload on the wire.

This issue affects OTP from OTP 25.0 before OTP 29.0.4, OTP 28.5.0.4 and OTP 27.3.4.15, corresponding to erts from 13.0 before 17.0.4, 16.4.0.4 and 15.2.7.11.

Database specific 
{
    "cna_assigner": "EEF",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/55xxx/CVE-2026-55737.json",
    "unresolved_ranges": [
        {
            "extracted_events": [
                {
                    "introduced": "13.0"
                },
                {
                    "fixed": "*"
                },
                {
                    "introduced": "25.0"
                },
                {
                    "fixed": "*"
                },
                {
                    "introduced": "ebcbb97b4ec223464cac3d94375739a248ddef6e"
                },
                {
                    "fixed": "c5210b42a9d3d96f3d25601942ce8122be0f3761"
                }
            ],
            "source": "AFFECTED_FIELD"
        },
        {
            "extracted_events": [
                {
                    "introduced": "25.0"
                },
                {
                    "fixed": "27.3.4.15"
                },
                {
                    "introduced": "28.0"
                },
                {
                    "fixed": "28.5.0.4"
                },
                {
                    "introduced": "29.0"
                },
                {
                    "fixed": "29.0.4"
                }
            ],
            "source": "CPE_FIELD"
        },
        {
            "extracted_events": [
                {
                    "introduced": "25.0"
                },
                {
                    "introduced": "13.0"
                },
                {
                    "fixed": "17.0.4"
                }
            ],
            "source": "DESCRIPTION"
        }
    ],
    "cwe_ids": [
        "CWE-195",
        "CWE-787"
    ]
}
References

Affected packages

Git / github.com/erlang/otp

Affected ranges

Type
GIT
Repo
https://github.com/erlang/otp
Events
Introduced
0 Unknown introduced commit / All previous commits are affected
Fixed
c5210b42a9d3d96f3d25601942ce8122be0f3761
Database specific 
{
    "source": "REFERENCES"
}

Affected versions

OTP-17.*
OTP-17.0
OTP-18.*
OTP-18.0
OTP-18.0-rc1
OTP-19.*
OTP-19.0
OTP-19.0-rc1
OTP-19.0-rc2
OTP-20.*
OTP-20.0
OTP-20.0-rc1
OTP-20.0-rc2
OTP-21.*
OTP-21.0
OTP-21.0-rc1
OTP-21.0-rc2
OTP-22.*
OTP-22.0
OTP-22.0-rc1
OTP-22.0-rc2
OTP-22.0-rc3
OTP-23.*
OTP-23.0
OTP-23.0-rc1
OTP-23.0-rc2
OTP-23.0-rc3
OTP-24.*
OTP-24.0
OTP-24.0-rc1
OTP-24.0-rc2
OTP-24.0-rc3
OTP-25.*
OTP-25.0
OTP-25.0-rc1
OTP-25.0-rc2
OTP-25.0-rc3
OTP-26.*
OTP-26.0
OTP-26.0-rc1
OTP-26.0-rc2
OTP-26.0-rc3
OTP-27.*
OTP-27.0
OTP-27.0-rc1
OTP-27.0-rc2
OTP-27.0-rc3
OTP-27.1
OTP-27.2
OTP-27.3
OTP-27.3.1
OTP-27.3.2
OTP-27.3.3
OTP-27.3.4
OTP_17.*
OTP_17.0-rc1
OTP_17.0-rc2
Other
OTP_R13B03
OTP_R13B04
OTP_R14A
OTP_R14B
OTP_R14B01
OTP_R14B02
OTP_R14B03
OTP_R15A
OTP_R15B
OTP_R16A_RELEASE_CANDIDATE
OTP_R16B
patch-base-27

Database specific

vanir_signatures_modified 
"2026-07-29T08:20:17Z"
vanir_signatures 
[
    {
        "target": {
            "function": "dec_term",
            "file": "erts/emulator/beam/external.c"
        },
        "id": "CVE-2026-55737-37372609",
        "digest": {
            "function_hash": "274620051191622708189806810367620417122",
            "length": 18355.0
        },
        "deprecated": false,
        "signature_version": "v1",
        "signature_type": "Function",
        "source": "https://github.com/erlang/otp/commit/c5210b42a9d3d96f3d25601942ce8122be0f3761"
    },
    {
        "target": {
            "function": "decoded_size",
            "file": "erts/emulator/beam/external.c"
        },
        "id": "CVE-2026-55737-61690b93",
        "digest": {
            "function_hash": "151631869666417194889055200798638607449",
            "length": 7049.0
        },
        "deprecated": false,
        "signature_version": "v1",
        "signature_type": "Function",
        "source": "https://github.com/erlang/otp/commit/c5210b42a9d3d96f3d25601942ce8122be0f3761"
    },
    {
        "target": {
            "file": "erts/emulator/beam/external.c"
        },
        "id": "CVE-2026-55737-fc08d775",
        "digest": {
            "line_hashes": [
                "163280457750676734900279870991134780414",
                "122596077993829045550579153013852990028",
                "14546037783706032069697512902558977241",
                "94422143658124507221783098213955201150",
                "306942062293879953335362107754943078575",
                "245130003002038853262703291213551869868",
                "9771150500771257063044300031309272034",
                "236013294772006922695479952280560046841",
                "249120499072289816206395365375493616732",
                "104431137102872275312802688813124292002",
                "197094389993450959993925167799689180472",
                "49081135807654127949625384542412245608"
            ],
            "threshold": 0.9
        },
        "deprecated": false,
        "signature_version": "v1",
        "signature_type": "Line",
        "source": "https://github.com/erlang/otp/commit/c5210b42a9d3d96f3d25601942ce8122be0f3761"
    }
]
source 
"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-55737.json"