How severe is CVE-2026-66274?

CVE-2026-66274 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2026-66274 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (40th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-66274?

CVE-2026-66274 affects Apache Qpid Proton-j. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-66274?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2026-66274 published?

CVE-2026-66274 was published on 2026-08-05 and last updated on 2026-08-07.

CVE-2026-66274

CVE-2026-66274 is a high-severity vulnerability in Apache Qpid Proton-j with a CVSS 3.x base score of 7.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-674.

Key facts

Severity: High (CVSS 3.x base score 7.5)
EPSS exploit prediction: 0% (40th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-674
Affected product: Apache Qpid Proton-j
Published: 2026-08-05
Last modified: 2026-08-07

Description

A pre-authentication attacker could leverage type nesting to cause a StackOverflowError potentially leading to denial of service. This issue affects Apache Qpid Proton-J: through 0.34.1. Users are recommended to upgrade to version 0.35.0, which fixes the issue.

Frequently asked questions

What is CVE-2026-66274?: A pre-authentication attacker could leverage type nesting to cause a StackOverflowError potentially leading to denial of service. This issue affects Apache Qpid Proton-J: through 0.34.1. Users are recommended to upgrade to version 0.35.0, which fixes the issue.
How severe is CVE-2026-66274?: CVE-2026-66274 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2026-66274 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (40th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-66274?: CVE-2026-66274 affects Apache Qpid Proton-j. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-66274?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2026-66274 published?: CVE-2026-66274 was published on 2026-08-05 and last updated on 2026-08-07.

References

Affected products (1)

cpe:2.3:a:apache:qpid_proton-j:*:*:*:*:*:*:*:*

More vulnerabilities in Apache Qpid Proton-j

CVE-2026-66273 — High (CVSS 7.5): A pre-authentication attacker could leverage type size/count handling to cause excessive allocation leading to…
CVE-2026-66257 — High (CVSS 7.5): A pre-authentication attacker could leverage unbounded symbol value caching to cause resource exhaustion leading to…
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CVE-2026-66276 — Medium (CVSS 6.5): An authenticated attacker can craft a disposition frame with large or illegal ranges causing excessive CPU usage due to…
CVE-2026-66275 — Medium (CVSS 6.5): An authenticated attacker could exceed the session flow control incoming window potentially leading to denial of…

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Other CWE-674 (Uncontrolled Recursion) vulnerabilities

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CVE-2021-41752 — Critical (CVSS 9.8): Stack overflow vulnerability in Jerryscript before commit e1ce7dd7271288be8c0c8136eea9107df73a8ce2 on Oct 20, 2021 due…
CVE-2018-1000618 — Critical (CVSS 9.8): EOSIO/eos eos version after commit f1545dd0ae2b77580c2236fdb70ae7138d2c7168 contains a stack overflow vulnerability in…
CVE-2025-10728 — Critical (CVSS 9.4): When the module renders a Svg file that contains a <pattern> element, it might end up rendering it recursively leading…
CVE-2026-32327 — Critical (CVSS 9.1): A bug in APR-util version 1.6.3 (and earlier) allows a stack recursion attack against any library consumer which parses…

Browse all CWE-674 (Uncontrolled Recursion) vulnerabilities →