Vulnerability-Lookup

GHSA-VGXX-5XJ5-Q97X

Vulnerability from github – Published: 2026-04-08 00:30 – Updated: 2026-05-12 15:31

Details

Issue summary: Applications using RSASVE key encapsulation to establish a secret encryption key can send contents of an uninitialized memory buffer to a malicious peer.

Impact summary: The uninitialized buffer might contain sensitive data from the previous execution of the application process which leads to sensitive data leakage to an attacker.

RSA_public_encrypt() returns the number of bytes written on success and -1 on error. The affected code tests only whether the return value is non-zero. As a result, if RSA encryption fails, encapsulation can still return success to the caller, set the output lengths, and leave the caller to use the contents of the ciphertext buffer as if a valid KEM ciphertext had been produced.

If applications use EVP_PKEY_encapsulate() with RSA/RSASVE on an attacker-supplied invalid RSA public key without first validating that key, then this may cause stale or uninitialized contents of the caller-provided ciphertext buffer to be disclosed to the attacker in place of the KEM ciphertext.

As a workaround calling EVP_PKEY_public_check() or EVP_PKEY_public_check_quick() before EVP_PKEY_encapsulate() will mitigate the issue.

The FIPS modules in 3.6, 3.5, 3.4, 3.3, 3.1 and 3.0 are affected by this issue.

Severity

7.5 (High)


                  
                    CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

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{
  "affected": [],
  "aliases": [
    "CVE-2026-31790"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-754"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-04-07T22:16:21Z",
    "severity": "HIGH"
  },
  "details": "Issue summary: Applications using RSASVE key encapsulation to establish\na secret encryption key can send contents of an uninitialized memory buffer to\na malicious peer.\n\nImpact summary: The uninitialized buffer might contain sensitive data from the\nprevious execution of the application process which leads to sensitive data\nleakage to an attacker.\n\nRSA_public_encrypt() returns the number of bytes written on success and -1\non error. The affected code tests only whether the return value is non-zero.\nAs a result, if RSA encryption fails, encapsulation can still return success to\nthe caller, set the output lengths, and leave the caller to use the contents of\nthe ciphertext buffer as if a valid KEM ciphertext had been produced.\n\nIf applications use EVP_PKEY_encapsulate() with RSA/RSASVE on an\nattacker-supplied invalid RSA public key without first validating that key,\nthen this may cause stale or uninitialized contents of the caller-provided\nciphertext buffer to be disclosed to the attacker in place of the KEM\nciphertext.\n\nAs a workaround calling EVP_PKEY_public_check() or\nEVP_PKEY_public_check_quick() before EVP_PKEY_encapsulate() will mitigate\nthe issue.\n\nThe FIPS modules in 3.6, 3.5, 3.4, 3.3, 3.1 and 3.0 are affected by this issue.",
  "id": "GHSA-vgxx-5xj5-q97x",
  "modified": "2026-05-12T15:31:15Z",
  "published": "2026-04-08T00:30:26Z",
  "references": [
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      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-31790"
    },
    {
      "type": "WEB",
      "url": "https://github.com/openssl/openssl/commit/001e01db3e996e13ffc72386fe79d03a6683b5ac"
    },
    {
      "type": "WEB",
      "url": "https://github.com/openssl/openssl/commit/abd8b2eec7e3f3fda60ecfb68498b246b52af482"
    },
    {
      "type": "WEB",
      "url": "https://github.com/openssl/openssl/commit/b922e24e5b23ffb9cb9e14cadff23d91e9f7e406"
    },
    {
      "type": "WEB",
      "url": "https://github.com/openssl/openssl/commit/d5f8e71cd0a54e961d0c3b174348f8308486f790"
    },
    {
      "type": "WEB",
      "url": "https://github.com/openssl/openssl/commit/eed200f58cd8645ed77e46b7e9f764e284df379e"
    },
    {
      "type": "WEB",
      "url": "https://cert-portal.siemens.com/productcert/html/ssa-032379.html"
    },
    {
      "type": "WEB",
      "url": "https://openssl-library.org/news/secadv/20260407.txt"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N",
      "type": "CVSS_V3"
    }
  ]
}

CVE-2026-31790 (GCVE-0-2026-31790)

Vulnerability from cvelistv5 – Published: 2026-04-07 22:00 – Updated: 2026-05-12 12:09

Title

Incorrect Failure Handling in RSA KEM RSASVE Encapsulation

Summary

Issue summary: Applications using RSASVE key encapsulation to establish a secret encryption key can send contents of an uninitialized memory buffer to a malicious peer. Impact summary: The uninitialized buffer might contain sensitive data from the previous execution of the application process which leads to sensitive data leakage to an attacker. RSA_public_encrypt() returns the number of bytes written on success and -1 on error. The affected code tests only whether the return value is non-zero. As a result, if RSA encryption fails, encapsulation can still return success to the caller, set the output lengths, and leave the caller to use the contents of the ciphertext buffer as if a valid KEM ciphertext had been produced. If applications use EVP_PKEY_encapsulate() with RSA/RSASVE on an attacker-supplied invalid RSA public key without first validating that key, then this may cause stale or uninitialized contents of the caller-provided ciphertext buffer to be disclosed to the attacker in place of the KEM ciphertext. As a workaround calling EVP_PKEY_public_check() or EVP_PKEY_public_check_quick() before EVP_PKEY_encapsulate() will mitigate the issue. The FIPS modules in 3.6, 3.5, 3.4, 3.3, 3.1 and 3.0 are affected by this issue.

Severity

7.5 (High)


                        
                          CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

SSVC

Exploitation: none Automatable: yes Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-04-08 14:32 UTC

CWE

CWE-754 - Improper Check for Unusual or Exceptional Conditions

Assigner

openssl mitre root

References

7 references

URL	Tags
https://openssl-library.org/news/secadv/20260407.txt	vendor-advisory
https://github.com/openssl/openssl/commit/abd8b2e…	patch
https://github.com/openssl/openssl/commit/001e01d…	patch
https://github.com/openssl/openssl/commit/d5f8e71…	patch
https://github.com/openssl/openssl/commit/b922e24…	patch
https://github.com/openssl/openssl/commit/eed200f…	patch
https://cert-portal.siemens.com/productcert/html/…

Impacted products

2 products

Vendor	Product	Version
OpenSSL	OpenSSL	Affected: 3.6.0 , < 3.6.2 (semver) Affected: 3.5.0 , < 3.5.6 (semver) Affected: 3.4.0 , < 3.4.5 (semver) Affected: 3.3.0 , < 3.3.7 (semver) Affected: 3.0.0 , < 3.0.20 (semver)
Siemens	SIMATIC CN 4100	Affected: 0 , < V5.0 (custom)

Date Public

2026-04-07 14:00

Credits

Simo Sorce (Red Hat) Nikola Pajkovsky

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Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Detection rules are retrieved from Rulezet.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.

Related by attack behaviour

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