CVE-2026-0994
CVE-2026-0994 is a high-severity vulnerability in Google Protobuf 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)
- CVSS v4: 8.2
- EPSS exploit prediction: 1% (45th percentile)
- Actively exploited: Not listed in CISA KEV
- EU (EUVD) id: EUVD-2026-4322
- Weakness: CWE-674
- Affected product: Google Protobuf
- Published:
- Last modified:
Description
A denial-of-service (DoS) vulnerability exists in google.protobuf.json_format.ParseDict() in Python, where the max_recursion_depth limit can be bypassed when parsing nested google.protobuf.Any messages. Due to missing recursion depth accounting inside the internal Any-handling logic, an attacker can supply deeply nested Any structures that bypass the intended recursion limit, eventually exhausting Python’s recursion stack and causing a RecursionError.
Frequently asked questions
- What is CVE-2026-0994?
- A denial-of-service (DoS) vulnerability exists in google.protobuf.json_format.ParseDict() in Python, where the max_recursion_depth limit can be bypassed when parsing nested google.protobuf.Any messages. Due to missing recursion depth accounting inside the internal Any-handling logic, an attacker can supply deeply nested Any structures that bypass the intended recursion limit, eventually exhausting Python’s recursion stack and causing a RecursionError.
- How severe is CVE-2026-0994?
- CVE-2026-0994 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-2026-0994 being actively exploited?
- It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (45th percentile), an estimate of the probability of exploitation in the next 30 days.
- What products are affected by CVE-2026-0994?
- CVE-2026-0994 affects Google Protobuf. See the affected-products list for the exact vulnerable versions.
- How do I fix CVE-2026-0994?
- 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.
- Does CVE-2026-0994 have an EU (EUVD) identifier?
- Yes. CVE-2026-0994 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-4322.
- When was CVE-2026-0994 published?
- CVE-2026-0994 was published on 2026-01-23 and last updated on 2026-06-30.
References
- https://github.com/protocolbuffers/protobuf/pull/25239
- https://access.redhat.com/errata/RHSA-2026:16174
- https://access.redhat.com/errata/RHSA-2026:3059
- https://access.redhat.com/errata/RHSA-2026:3094
- https://access.redhat.com/errata/RHSA-2026:3095
- https://access.redhat.com/errata/RHSA-2026:3097
- https://access.redhat.com/errata/RHSA-2026:3218
- https://access.redhat.com/errata/RHSA-2026:3219
- https://access.redhat.com/errata/RHSA-2026:3220
- https://access.redhat.com/errata/RHSA-2026:3461
- https://access.redhat.com/errata/RHSA-2026:3462
- https://access.redhat.com/errata/RHSA-2026:3958
- https://access.redhat.com/errata/RHSA-2026:3959
- https://access.redhat.com/errata/RHSA-2026:8746
- https://access.redhat.com/errata/RHSA-2026:8747
- https://access.redhat.com/errata/RHSA-2026:8748
- https://access.redhat.com/security/cve/CVE-2026-0994
- https://bugzilla.redhat.com/show_bug.cgi?id=2432398
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-0994.json
Affected products (1)
- cpe:2.3:a:google:protobuf:*:*:*:*:*:*:*:*
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