CVE-2026-61695
Wire Swift runtime: negative LENGTH_DELIMITED length in skipGroup() crashes any protobuf-decoding service
Description
Wire provides gRPC and protocol buffers for Android, Kotlin, Swift, and Java. Prior to 6.4.1 and 7.0.0-alpha04, Wire's Swift runtime ProtoReader.skipGroup(expectedEndTag:unknownFieldsWriter:) accepts a negative length for a LENGTH_DELIMITED field inside an unknown START_GROUP field. ProtoReader.readData() forwards the negative count to ReadBuffer.readData(count:), whose upper-bound-only check permits the value to reach Foundation Data(bytes:count:) and trigger an unrecoverable process trap instead of a catchable ProtoDecoder.Error. Any Swift process decoding untrusted protobuf bytes can be crashed without authentication, user interaction, or knowledge of the target schema. This issue is fixed in versions 6.4.1 and 7.0.0-alpha04.
INFO
Published Date :
Sept. 23, 2026, 7:17 p.m.
Last Modified :
Sept. 30, 2026, 7:38 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
Affected Products
The following products are affected by CVE-2026-61695
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
No affected product recoded yet
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | |||||
| CVSS 3.1 | HIGH | MITRE-CVE | ||||
| CVSS 3.1 | HIGH | [email protected] |
Solution
- Update Wire to version 6.4.1 or later.
- Update Wire to version 7.0.0-alpha04 or later.
- Ensure negative lengths are handled correctly in ProtoReader.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-61695.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-61695 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-61695
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-61695 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-61695 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Sep. 29, 2026
Action Type Old Value New Value Added Reference https://github.com/square/wire/security/advisories/GHSA-86wm-r4c5-2rc9 Added SSVC {'id': 'CVE-2026-61695', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'poc'}, {'automatable': 'yes'}, {'technicalImpact': 'partial'}], 'version': '2.0.3', 'timestamp': '2026-09-29T02:07:04.183481Z'} -
New CVE Received by [email protected]
Sep. 23, 2026
Action Type Old Value New Value Added Description Wire provides gRPC and protocol buffers for Android, Kotlin, Swift, and Java. Prior to 6.4.1 and 7.0.0-alpha04, Wire's Swift runtime ProtoReader.skipGroup(expectedEndTag:unknownFieldsWriter:) accepts a negative length for a LENGTH_DELIMITED field inside an unknown START_GROUP field. ProtoReader.readData() forwards the negative count to ReadBuffer.readData(count:), whose upper-bound-only check permits the value to reach Foundation Data(bytes:count:) and trigger an unrecoverable process trap instead of a catchable ProtoDecoder.Error. Any Swift process decoding untrusted protobuf bytes can be crashed without authentication, user interaction, or knowledge of the target schema. This issue is fixed in versions 6.4.1 and 7.0.0-alpha04. Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Added CWE CWE-129 Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/61xxx/CVE-2026-61695.json">CVE-2026-61695</a> Added Reference https://github.com/square/wire/commit/24043b6b3a5e5974a978f2745b76d50b31407c1c Added Reference https://github.com/square/wire/commit/81ff7f24a6795d9a8be2e03f272b2d979a5d2c7e Added Reference https://github.com/square/wire/pull/3616 Added Reference https://github.com/square/wire/releases/tag/6.4.1 Added Reference https://github.com/square/wire/releases/tag/7.0.0-alpha04 Added Reference https://github.com/square/wire/security/advisories/GHSA-86wm-r4c5-2rc9