CVE-2026-34180

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Source
https://cve.org/CVERecord?id=CVE-2026-34180
Import Source
https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-34180.json
JSON Data
https://api.osv.dev/v1/vulns/CVE-2026-34180
Downstream
Related
Published
2026-06-09T16:03:17.082Z
Modified
2026-07-15T17:36:06.935939Z
Severity
  • 7.5 (High) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H CVSS Calculator
Summary
Heap Buffer Over-read in ASN.1 Content Parsing
Details

Issue summary: Parsing a crafted DER-encoded ASN.1 structure with a primitive element whose content exceeds 2 gigabytes in length may cause a heap buffer over-read on 64-bit Unix and Unix-like platforms.

Impact summary: The heap buffer over-read may crash the application (Denial of Service) or to load into the decoded ASN.1 object contents of memory beyond the end of the input buffer. More typically such ASN.1 elements would instead be truncated.

An integer truncation in OpenSSL's ASN.1 decoder causes the content length of an ASN.1 primitive element to be mishandled when it exceeds 2 gigabytes. In the worst case the truncated length is treated as a request to scan the binary content for a terminating zero byte, possibly causing OpenSSL to read either less than or beyond the end of the allocated buffer.

Applications that pass attacker-supplied data to d2iX509(), d2iPKCS7(), or any other d2i_* decoding function are affected. OpenSSL's own command-line tools are not vulnerable, as data read through the BIO layer is checked before it reaches the affected code. The issue only affects 64-bit Unix and Unix-like platforms; 32-bit platforms and 64-bit Windows are not affected.

The FIPS modules in 4.0, 3.6, 3.5, 3.4 and 3.0 are not affected by this issue, as the affected code is outside the OpenSSL FIPS module boundary.

Database specific 
{
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/34xxx/CVE-2026-34180.json",
    "cna_assigner": "openssl",
    "cwe_ids": [
        "CWE-125"
    ]
}
References

Affected packages

Git / github.com/openssl/openssl

Affected ranges

Type
GIT
Repo
https://github.com/openssl/openssl
Events
Introduced
e818b74be2170fbe957a07b0da4401c2b694b3b8
Fixed
e818b74be2170fbe957a07b0da4401c2b694b3b8
Introduced
e04bd3433fd84e1861bf258ea37928d9845e6a86
Fixed
e04bd3433fd84e1861bf258ea37928d9845e6a86
Introduced
89cd17a031e022211684eb7eb41190cf1910f9fa
Fixed
51ea949dc1436e865935b47874b21a3bb31a102e
Introduced
98acb6b02839c609ef5b837794e08d906d965335
Fixed
c5ea1cc227fd60afae8ac4b9438690bbe4888f79
Introduced
636dfadc70ce26f2473870570bfd9ec352806b1d
Fixed
8cf17aaeb4599f8af87fefd810b5b5fee90fe69e
Introduced
7b371d80d959ec9ab4139d09d78e83c090de9779
Fixed
aae016bfd52fcad2bc9657c2c782cfdf73b1ed5f
Introduced
11b7b6ea3b65a584e1d31408ed1bdb139465cffd
Fixed
1c6908e4fa5fa568752221d8eaf561a809751e5d
Fixed
cbe418ae978539cf14a398a207dba834c0e93e83
Fixed
d93853c42110d6319e3df07842b488cb9f7ac5ff
Fixed
da5d62af75f69d6fbf7803743d7c56ac75461e43
Fixed
f696c73c3e61b8c502d040af62e690c060908a16
Database specific 
{
    "cpe": [
        "cpe:2.3:a:openssl:openssl:*:*:*:*:*:*:*:*",
        "cpe:2.3:a:openssl:openssl:4.0.0:-:*:*:*:*:*:*"
    ],
    "source": [
        "CPE_RANGE",
        "CPE_STRING",
        "REFERENCES"
    ],
    "extracted_events": [
        {
            "introduced": "1.0.2"
        },
        {
            "fixed": "1.0.2zq"
        },
        {
            "introduced": "1.1.1"
        },
        {
            "fixed": "1.1.1zh"
        },
        {
            "introduced": "3.0.0"
        },
        {
            "fixed": "3.0.21"
        },
        {
            "introduced": "3.4.0"
        },
        {
            "fixed": "3.4.6"
        },
        {
            "introduced": "3.5.0"
        },
        {
            "fixed": "3.5.7"
        },
        {
            "introduced": "3.6.0"
        },
        {
            "fixed": "3.6.3"
        },
        {
            "introduced": "4.0.0-NA"
        },
        {
            "last_affected": "4.0.0-NA"
        }
    ]
}

Affected versions

3.*
3.0-POST-CLANG-FORMAT-WEBKIT
3.0-PRE-CLANG-FORMAT-WEBKIT
3.4-POST-CLANG-FORMAT-WEBKIT
3.4-PRE-CLANG-FORMAT-WEBKIT
3.5-POST-CLANG-FORMAT-WEBKIT
3.5-PRE-CLANG-FORMAT-WEBKIT
3.6-POST-CLANG-FORMAT-WEBKIT
3.6-PRE-CLANG-FORMAT-WEBKIT
4.*
4.0.0-NA
openssl-3.*
openssl-3.0.0
openssl-3.0.1
openssl-3.0.10
openssl-3.0.11
openssl-3.0.12
openssl-3.0.13
openssl-3.0.14
openssl-3.0.15
openssl-3.0.16
openssl-3.0.17
openssl-3.0.18
openssl-3.0.19
openssl-3.0.2
openssl-3.0.20
openssl-3.0.3
openssl-3.0.4
openssl-3.0.5
openssl-3.0.6
openssl-3.0.7
openssl-3.0.8
openssl-3.0.9
openssl-3.4.0
openssl-3.4.1
openssl-3.4.2
openssl-3.4.3
openssl-3.4.4
openssl-3.4.5
openssl-3.5.0
openssl-3.5.1
openssl-3.5.2
openssl-3.5.3
openssl-3.5.4
openssl-3.5.5
openssl-3.5.6
openssl-3.6.0
openssl-3.6.1
openssl-3.6.2
openssl-4.*
openssl-4.0.0

Database specific

vanir_signatures 
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        },
        "id": "CVE-2026-34180-3938e24c",
        "deprecated": false
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        "signature_type": "Line",
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        },
        "id": "CVE-2026-34180-5268d8ae",
        "deprecated": false
    },
    {
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            ]
        },
        "signature_version": "v1",
        "source": "https://github.com/openssl/openssl/commit/f696c73c3e61b8c502d040af62e690c060908a16",
        "signature_type": "Line",
        "target": {
            "file": "crypto/asn1/tasn_dec.c"
        },
        "id": "CVE-2026-34180-e0e0a062",
        "deprecated": false
    }
]
vanir_signatures_modified 
"2026-07-15T17:36:06Z"
source 
"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-34180.json"