CVE-2026-61695Wire Swift runtime: negative LENGTH_DELIMITED length in skipGroup() crashes any protobuf-decoding service
- 7.5HighCVSS base score
- 0.69%Exploitation in 30 daysEPSS · top 47% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- YesPublic exploitsa reference or SSVC says so
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.
Public exploit
An exploit or proof of concept is public: anyone can try it against an unpatched system. A reference of the record is tagged as an exploit. CISA's SSVC rates its exploitation: a proof of concept is public.
Show the exploits1
References tagged exploit1 reference
- https://github.com/square/wire/security/advisories/GHSA-86wm-r4c5-2rc9 (opens in a new tab)x_refsource_CONFIRMexploit
Timeline
ID reserved
By GitHub_M
- 3 months later
· 3 months later
Published
- 6 days later
· 6 days later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| GitHub_MCNA (assigner) | 3.1 | High7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
| NVDNVD · Awaiting Analysis | 3.1 | High7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
- EPSS (exploitation in 30 days)
- 0.69% · top 47% of all CVEs (14 Nov 2026)
- CISA SSVC
- Exploitation: poc · Automatable: yes · Technical impact: partial
The list uses the assigner's score when there is one, then CISA's, then NVD's: High 7.5.
Affected products
Affected packages
From reviewed advisories of the GitHub Advisory Database.
- SwiftURLgithub.com/square/wireGHSA-86wm-r4c5-2rc9 (opens in a new tab)
References
References6
- https://github.com/square/wire/security/advisories/GHSA-86wm-r4c5-2rc9 (opens in a new tab)x_refsource_CONFIRMexploit
- https://github.com/square/wire/pull/3616 (opens in a new tab)x_refsource_MISC
- https://github.com/square/wire/commit/24043b6b3a5e5974a978f2745b76d50b31407c1c (opens in a new tab)x_refsource_MISC
- https://github.com/square/wire/commit/81ff7f24a6795d9a8be2e03f272b2d979a5d2c7e (opens in a new tab)x_refsource_MISC
- https://github.com/square/wire/releases/tag/6.4.1 (opens in a new tab)x_refsource_MISC
- https://github.com/square/wire/releases/tag/7.0.0-alpha04 (opens in a new tab)x_refsource_MISC
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2026-85559 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisory GHSA-86wm-r4c5-2rc9 (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2026-61695)Record last updated .