CVE-2026-69186

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Source
https://cve.org/CVERecord?id=CVE-2026-69186
Import Source
https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-69186.json
JSON Data
https://api.test.osv.dev/v1/vulns/CVE-2026-69186
Aliases
  • GHSA-jv8r-gqr9-68wj
Downstream
AZL (1)
BELL (1)
DEBIAN (1)
MGASA (1)
openSUSE (2)
SUSE (3)
UBUNTU (1)
Related
openSUSE (2)
SUSE (3)
Published
2026-09-18T17:25:42Z
Modified
2026-09-20T08:19:49Z
Severity
  • 5.3 (Medium) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L CVSS Calculator
Summary
c-ares: Memory-amplification denial of service via unvalidated DNS header record counts
Details

c-ares is an asynchronous resolver library. Prior to 1.34.7, ares_dns_parse() trusts the attacker-controlled ANCOUNT, NSCOUNT, and ARCOUNT fields before confirming that the DNS response contains enough bytes for the claimed records. Because process_answer() invokes parsing before transaction ID and question validation, a malicious DNS response can cause ares_dns_record_rr_prealloc() and ares_array_set_size() to reserve disproportionate heap memory for a tiny message. Repeated responses create large allocation and release cycles that can degrade or deny name resolution, without causing memory corruption or information disclosure. This issue is fixed in version 1.34.7.

Database specific 
{
    "cna_assigner":  "GitHub_M",
    "cwe_ids":  [
        "CWE-400"
    ],
    "osv_generated_from":  "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/69xxx/CVE-2026-69186.json"
}
References

Affected packages

Git / github.com/c-ares/c-ares

Affected ranges

Type
GIT
Repo
https://github.com/c-ares/c-ares
Events
Introduced
0 Unknown introduced commit / All previous commits are affected
Fixed
e47c203f91cd8b749c8736bc18d75a31ffdec8f4
Fixed
eaded4cb200b2a5f8d73f11021ff7c8d6968aaab
Fixed
d63b7de3a3568d14ab1351374b205365aed51cca
Database specific
Show details 
{
    "extracted_events":  [
        {
            "introduced":  "0"
        },
        {
            "fixed":  "1.34.7"
        }
    ],
    "source":  [
        "AFFECTED_FIELD",
        "REFERENCES"
    ]
}

Affected versions

Other
c-ares-1_17_0
c-ares-1_2_0
cares-1_10_0
cares-1_11_0
cares-1_11_0-rc1
cares-1_12_0
cares-1_13_0
cares-1_14_0
cares-1_15_0
cares-1_16_0
cares-1_16_1
cares-1_17_1
cares-1_17_2
cares-1_18_0
cares-1_18_1
cares-1_19_0
cares-1_19_1
cares-1_1_0
cares-1_20_0
cares-1_20_1
cares-1_21_0
cares-1_22_0
cares-1_22_1
cares-1_23_0
cares-1_24_0
cares-1_25_0
cares-1_26_0
cares-1_27_0
cares-1_28_0
cares-1_28_1
cares-1_29_0
cares-1_2_1
cares-1_3_1
cares-1_3_2
cares-1_4_0
cares-1_5_0
cares-1_5_1
cares-1_5_2
cares-1_5_3
cares-1_6_0
cares-1_7_0
cares-1_7_1
cares-1_7_2
cares-1_7_3
cares-1_7_4
cares-1_7_5
cares-1_8_0
cares-1_9_0
cares-1_9_1
curl-7_10_8
curl-7_11_0
curl-7_11_1
curl-7_12_0
curl-7_12_1
curl-7_12_2
curl-7_13_0
curl-7_13_1
curl-7_13_2
curl-7_14_0
curl-7_14_1
curl-7_15_0
curl-7_15_1
curl-7_15_3
curl-7_15_4
curl-7_15_5
curl-7_15_6-prepipeline
curl-7_16_0
curl-7_16_1
curl-7_16_2
curl-7_16_3
curl-7_16_4
curl-7_17_0
curl-7_17_1
curl-7_18_0
curl-7_18_1
curl-7_18_2
curl-7_19_0
curl-7_19_2
curl-7_19_3
curl-7_19_4
curl-7_19_5
curl-7_19_6
curl-7_19_7
curl-7_20_0
v1.*
v1.31.0
v1.34.0
v1.34.1
v1.34.2
v1.34.3
v1.34.4
v1.34.5
v1.34.6

Database specific

source 
"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-69186.json"
vanir_signatures 
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        "deprecated":  false,
        "digest":  {
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        },
        "id":  "CVE-2026-69186-03106c5a",
        "signature_type":  "Function",
        "signature_version":  "v1",
        "source":  "https://github.com/c-ares/c-ares/commit/eaded4cb200b2a5f8d73f11021ff7c8d6968aaab",
        "target":  {
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            "function":  "ares_dns_parse_header"
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        "target":  {
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        "target":  {
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        }
    },
    {
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        "digest":  {
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        }
    },
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        "digest":  {
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        "target":  {
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        }
    },
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]
vanir_signatures_modified 
"2026-09-20T08:19:49Z"