jackson-dataformat-protobuf: Integer Overflow or Wraparound
CVE-2026-104016 is a high-severity integer overflow or wraparound vulnerability in jackson-dataformat-protobuf from FasterXML, with a CVSS 3.1 base score of 7.5 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. The record lists versions 2.18.12, 2.21.8, 2.22.4 as the first without the flaw, so updating jackson-dataformat-protobuf to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.68% chance of exploitation within 30 days, higher than 53% of scored CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update jackson-dataformat-protobuf to 2.18.12 or 2.21.8 or 2.22.4 or 3.1.8, whichever matches your release line, or a later version.
- Read the advisory on github.com for workarounds and exact fixed builds.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| FasterXML | jackson-dataformat-protobuf | 2.6.0 up to, but not including, 2.18.12; 2.19.0 up to, but not including, 2.21.8; 2.22.0 up to, but not including, 2.22.4; 3.0.0 up to, but not including, 3.1.8; 3.2.0 up to, but not including, 3.2.4 | 2.18.12, 2.21.8, 2.22.4, 3.1.8, 3.2.4 |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- NoneNo data is disclosed.
- Integrity
- NoneNothing can be modified.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H. Scored by CNA.
Official description
ProtobufParser parses length-prefixed protobuf string and bytes fields by checking (_inputPtr + len) <= _inputEnd and then, on the fast path, calling _finishShortText(len). Both use 32-bit signed integer arithmetic. When an attacker supplies a varint decoding to a length near Integer.MAX_VALUE, _inputPtr + len overflows to a negative value, the bounds check passes, and _finishShortText(len) reaches TextBuffer.expandCurrentSegment(len), which performs Arrays.copyOf with no cap and throws OutOfMemoryError: Requested array size exceeds VM limit. The JVM refuses arrays larger than Integer.MAX_VALUE - 8 before consulting available heap, so -Xmx tuning does not mitigate the issue. StreamReadConstraints.maxStringLength and maxDocumentLength do not gate this path: a 33-byte payload is far below any document-length cap and the string-length check does not fire before the allocation. This was confirmed empirically against shipping artifacts with maxStringLength, maxDocumentLength and maxNestingDepth all configured. A February 2026 hardening commit added the equivalent overflow guard to the packed-array-length and message-length paths but left the string-length call sites unguarded. No privileges or user interaction beyond the ability to submit data for parsing are required.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Integer Overflow or Wraparound
The product performs a calculation that can produce an integer overflow or wraparound when the logic assumes that the resulting value will always be larger than the original value. This occurs when an integer value is incremented to a value that is too large to store in the associated representation. When this occurs, the value may become a very small or negative number.
How developers prevent this class of flaw
- Ensure that all protocols are strictly defined, such that all out-of-bounds behavior can be identified simply, and require strict conformance to the protocol.
- Use a language that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. If possible, choose a language or compiler that performs automatic bounds checking.
- Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. Use libraries or frameworks that make it easier to handle numbers without unexpected consequences. Examples include safe integer handling packages such as SafeInt (C++) or IntegerLib (C or C++).
More Integer Overflow or Wraparound vulnerabilities (CWE-190)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: yes, technical impact: partial).
- Record last changed materially (score, affected products, status or references).
References
Other vulnerabilities in jackson-dataformat-protobuf
- 7.5 High severity
Recent Integer Overflow or Wraparound vulnerabilities
- 9.1 Critical severity
- 7.5 High severity
- 7.2 High severity
- 7.2 High severity
- 8.2 High severity
- 8.8 High severity
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