Vulnerability-Lookup

OESA-2026-3793 (CVE-2026-18374)

Vulnerability from osv_openeuler – Published: 2026-09-14 16:34 – Updated: 2026-09-14 16:34 – Source website

Summary

glibc security update

Details

The GNU C Library project provides the core libraries for the GNU system and GNU/Linux systems, as well as many other systems that use Linux as the kernel. These libraries provide critical APIs including ISO C11, POSIX.1-2008, BSD, OS-specific APIs and more. These APIs include such foundational facilities as open, read, write, malloc, printf, getaddrinfo, dlopen, pthread_create, crypt, login, exit and more.

Security Fix(es):

Passing an effectively empty string to the ,ccs= syntax extension of the mode argument in the fopen function in the GNU C Library version 2.45 or earlier may result in a heap buffer overflow when the mode string input to the function is attacker controlled. This usage pattern is not seen in applications in common GNU/Linux distributions and applications that process user-supplied values for ccs should not pass them through without validation.(CVE-2026-18374)

Severity

4.9 (Medium)


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

References

URL

Type

	https://www.openeuler.org/zh/security/security-bu…	ADVISORY
	https://nvd.nist.gov/vuln/detail/CVE-2026-18374	ADVISORY

JSON

To clipboard

{
  "affected": [
    {
      "ecosystem_specific": {
        "aarch64": [
          "glibc-2.28-132.oe2003sp4.aarch64.rpm",
          "glibc-all-langpacks-2.28-132.oe2003sp4.aarch64.rpm",
          "glibc-benchtests-2.28-132.oe2003sp4.aarch64.rpm",
          "glibc-common-2.28-132.oe2003sp4.aarch64.rpm",
          "glibc-compat-2.17-2.28-132.oe2003sp4.aarch64.rpm",
          "glibc-debuginfo-2.28-132.oe2003sp4.aarch64.rpm",
          "glibc-debugsource-2.28-132.oe2003sp4.aarch64.rpm",
          "glibc-debugutils-2.28-132.oe2003sp4.aarch64.rpm",
          "glibc-devel-2.28-132.oe2003sp4.aarch64.rpm",
          "glibc-locale-source-2.28-132.oe2003sp4.aarch64.rpm",
          "glibc-nss-devel-2.28-132.oe2003sp4.aarch64.rpm",
          "libnsl-2.28-132.oe2003sp4.aarch64.rpm",
          "nscd-2.28-132.oe2003sp4.aarch64.rpm",
          "nss_modules-2.28-132.oe2003sp4.aarch64.rpm"
        ],
        "noarch": [
          "glibc-help-2.28-132.oe2003sp4.noarch.rpm"
        ],
        "src": [
          "glibc-2.28-132.oe2003sp4.src.rpm"
        ],
        "x86_64": [
          "glibc-2.28-132.oe2003sp4.x86_64.rpm",
          "glibc-all-langpacks-2.28-132.oe2003sp4.x86_64.rpm",
          "glibc-benchtests-2.28-132.oe2003sp4.x86_64.rpm",
          "glibc-common-2.28-132.oe2003sp4.x86_64.rpm",
          "glibc-compat-2.17-2.28-132.oe2003sp4.x86_64.rpm",
          "glibc-debuginfo-2.28-132.oe2003sp4.x86_64.rpm",
          "glibc-debugsource-2.28-132.oe2003sp4.x86_64.rpm",
          "glibc-debugutils-2.28-132.oe2003sp4.x86_64.rpm",
          "glibc-devel-2.28-132.oe2003sp4.x86_64.rpm",
          "glibc-locale-source-2.28-132.oe2003sp4.x86_64.rpm",
          "glibc-nss-devel-2.28-132.oe2003sp4.x86_64.rpm",
          "libnsl-2.28-132.oe2003sp4.x86_64.rpm",
          "nscd-2.28-132.oe2003sp4.x86_64.rpm",
          "nss_modules-2.28-132.oe2003sp4.x86_64.rpm"
        ]
      },
      "package": {
        "ecosystem": "openEuler:20.03-LTS-SP4",
        "name": "glibc",
        "purl": "pkg:rpm/openEuler/glibc\u0026distro=openEuler-20.03-LTS-SP4"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "2.28-132.oe2003sp4"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "database_specific": {
    "severity": "Medium"
  },
  "details": "The GNU C Library project provides the core libraries for the GNU system and GNU/Linux systems, as well as many other systems that use Linux as the kernel. These libraries provide critical APIs including ISO C11, POSIX.1-2008, BSD, OS-specific APIs and more. These APIs include such foundational facilities as open, read, write, malloc, printf, getaddrinfo, dlopen, pthread_create, crypt,  login, exit and more.\r\n\r\nSecurity Fix(es):\n\nPassing an effectively empty string to the `,ccs=` syntax extension of the mode argument in the `fopen` function in the GNU C Library version 2.45 or earlier may result in a heap buffer overflow when the mode string input to the function is attacker controlled. This usage pattern is not seen in applications in common GNU/Linux distributions and applications that process user-supplied values for `ccs` should not pass them through without validation.(CVE-2026-18374)",
  "id": "OESA-2026-3793",
  "modified": "2026-09-14T16:34:25Z",
  "published": "2026-09-14T16:34:25Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://www.openeuler.org/zh/security/security-bulletins/detail/?id=openEuler-SA-2026-3793"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-18374"
    }
  ],
  "schema_version": "1.7.2",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L",
      "type": "CVSS_V3"
    }
  ],
  "summary": "glibc security update",
  "upstream": [
    "CVE-2026-18374"
  ]
}

CVE-2026-18374 (GCVE-0-2026-18374)

Vulnerability from cvelistv5 – Published: 2026-08-27 19:20 – Updated: 2026-08-28 15:37

Summary

Passing an effectively empty string to the `,ccs=` syntax extension of the mode argument in the `fopen` function in the GNU C Library version 2.45 or earlier may result in a heap buffer overflow when the mode string input to the function is attacker controlled. This usage pattern is not seen in applications in common GNU/Linux distributions and applications that process user-supplied values for `ccs` should not pass them through without validation.

Severity

4.9 (Medium)


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

SSVC

Exploitation: none Automatable: no Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-08-28 15:36 UTC

CWE

Buffer overflow in fopen mode argument processing
CWE-787 - Out-of-bounds write
CWE-787 - Out-of-bounds Write

Assigner

glibc redhat root

References

3 references

URL	Tags
https://sourceware.org/bugzilla/show_bug.cgi?id=34574	issue-tracking
https://sourceware.org/git/?p=glibc.git;a=blob_pl…	vendor-advisory
http://www.openwall.com/lists/oss-security/2026/08/27/6

Impacted products

1 product

Vendor	Product	Version
The GNU C Library	glibc	Affected: 0 , < 2.45 (custom)

Show details on NVD website

JSON

To clipboard

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          "dateUpdated": "2026-08-27T22:21:53.526Z",
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        "metrics": [
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                  },
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      "metrics": [
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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

Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.