CVE-2026-35189 (GCVE-0-2026-35189)

Vulnerability from cvelistv5 – Published: 2026-09-29 15:32 – Updated: 2026-11-10 12:45
VLAI
Title
Excessive Memory Allocation in Relative CRLDP Processing
Summary
Issue summary: A certificate with many nameRelativeToCRLIssuer CRL distribution points causes disproportionate heap growth when OpenSSL caches X.509 extensions. Impact summary: Receiving a crafted certificate from a malicious peer can lead to significant memory pressure and possible Denial of Service in clients or in servers that solicit client certificates. CWE: CWE-770: Allocation of Resources Without Limits or Throttling Description: A certificate or a set of certificates that fits under the limit for size of certificates accepted from the peer (~100 KiB) can result in allocation of several hundred MiB of resident memory on the receiving side during a normal TLS handshake. This may be enough to crash the client or server, if multiple concurrent connections lead to similarly large memory allocations. The fix postpones processing of the CRL distribution points extensions in certificates to the time when the processed value is required for CRL processing. This avoids keeping large memory allocations for a long time when such certificates are received. FIPS impact: no The affected code is outside the FIPS module boundary.
Severity
5.3 (Medium)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
SSVC
Exploitation: none Automatable: yes Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-09-30 19:36 UTC
CWE
  • CWE-770 - Allocation of Resources Without Limits or Throttling
Assigner
openssl CNA under the mitre root
CNA scorecard B 78/100 over 48 records in the last 180 days details
References
Impacted products
Vendor Product Version CPE status
OpenSSL OpenSSL Affected: 4.0.0 , < 4.0.3 (semver)
Affected: 3.6.0 , < 3.6.5 (semver)
Affected: 3.5.0 , < 3.5.9 (semver)
Affected: 3.4.0 , < 3.4.8 (semver)
Affected: 3.0.0 , < 3.0.23 (semver)
Affected: 1.1.1 , < 1.1.1zj (custom)
Affected: 1.0.2 , < 1.0.2zs (custom)
guessed Create a notification for this product.
Siemens SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AB0) Affected: V3.1.7 , < * (custom)
guessed Create a notification for this product.
Siemens SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AC0) Affected: V3.1.7 , < * (custom)
guessed Create a notification for this product.
Siemens SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AB0) Affected: V3.1.7 , < * (custom)
guessed Create a notification for this product.
Siemens SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AC0) Affected: V3.1.7 , < * (custom)
guessed Create a notification for this product.
Siemens SIPLUS S7-1500 CPU 1518-4 PN/DP MFP (6AG1518-4AX00-4AC0) Affected: V3.1.7 , < * (custom)
guessed Create a notification for this product.
Date Public
2026-09-29 14:21
Credits
Fuzz0x (ZKSC Institute of Security Research) Viktor Dukhovni
Show details on NVD website
To clipboard 

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            "source": "openssl-security@openssl.org",
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          },
          {
            "source": "0b142b55-0307-4c5a-b3c9-f314f3fb7c5e",
            "url": "https://cert-portal.siemens.com/productcert/html/ssa-457936.html"
          }
        ],
        "sourceIdentifier": "openssl-security@openssl.org",
        "vulnStatus": "Modified",
        "weaknesses": [
          {
            "description": [
              {
                "lang": "en",
                "value": "CWE-770"
              }
            ],
            "source": "openssl-security@openssl.org",
            "type": "Secondary"
          }
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    },
    "redhat_vex": {
      "aggregate_severity": "Low",
      "current_release_date": "2026-11-11T12:09:37+00:00",
      "cve": "CVE-2026-35189",
      "id": "CVE-2026-35189",
      "initial_release_date": "2026-09-29T15:32:11.889000+00:00",
      "product_status:fixed": "112",
      "product_status:known_affected": "66",
      "product_status:known_not_affected": "21",
      "product_status:under_investigation": "17",
      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "openssl: openssl: Denial of Service via excessive memory allocation in CRL distribution point processing",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-35189.json",
      "version": "3"
    },
    "vulnrichment": {
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              "orgId": "0b142b55-0307-4c5a-b3c9-f314f3fb7c5e",
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                  "attackVector": "NETWORK",
                  "availabilityImpact": "LOW",
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                  "baseSeverity": "MEDIUM",
                  "confidentialityImpact": "NONE",
                  "integrityImpact": "NONE",
                  "privilegesRequired": "NONE",
                  "scope": "UNCHANGED",
                  "userInteraction": "NONE",
                  "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L",
                  "version": "3.1"
                }
              },
              {
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                    "options": [
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                      },
                      {
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                      },
                      {
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                    ],
                    "role": "CISA Coordinator",
                    "timestamp": "2026-09-30T19:36:26.041392Z",
                    "version": "2.0.3"
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              "dateUpdated": "2026-09-30T19:36:20.345Z",
              "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
              "shortName": "CISA-ADP"
            },
            "title": "CISA ADP Vulnrichment"
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        ],
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              "defaultStatus": "unaffected",
              "product": "OpenSSL",
              "vendor": "OpenSSL",
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                  "status": "affected",
                  "version": "4.0.0",
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          "credits": [
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              "type": "reporter",
              "value": "Fuzz0x (ZKSC Institute of Security Research)"
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            {
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              "type": "remediation developer",
              "value": "Viktor Dukhovni"
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          ],
          "datePublic": "2026-09-29T14:21:57.000Z",
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              "supportingMedia": [
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                  "value": "Issue summary: A certificate with many nameRelativeToCRLIssuer CRL\u003cbr\u003edistribution points causes disproportionate heap growth when OpenSSL caches\u003cbr\u003eX.509 extensions.\u003cbr\u003e\u003cbr\u003eImpact summary: Receiving a crafted certificate from a malicious peer can lead\u003cbr\u003eto significant memory pressure and possible Denial of Service in clients or\u003cbr\u003ein servers that solicit client certificates.\u003cbr\u003e\u003cbr\u003eCWE: CWE-770: Allocation of Resources Without Limits or Throttling\u003cbr\u003e\u003cbr\u003eDescription: A certificate or a set of certificates that fits under the limit for\u003cbr\u003esize of certificates accepted from the peer (~100 KiB) can result in allocation\u003cbr\u003eof several hundred MiB of resident memory on the receiving side\u003cbr\u003eduring a normal TLS handshake.  This may be enough to crash the client or\u003cbr\u003eserver, if multiple concurrent connections lead to similarly large memory\u003cbr\u003eallocations.\u003cbr\u003e\u003cbr\u003eThe fix postpones processing of the CRL distribution points extensions in\u003cbr\u003ecertificates to the time when the processed value is required for CRL processing.\u003cbr\u003eThis avoids keeping large memory allocations for a long time when such\u003cbr\u003ecertificates are received.\u003cbr\u003e\u003cbr\u003eFIPS impact: no\u003cbr\u003eThe affected code is outside the FIPS module boundary."
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        "datePublished": "2026-09-29T15:32:11.889Z",
        "dateReserved": "2026-04-01T17:36:26.323Z",
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    }
  }
}



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Sightings

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