info leak uploading over WebSockets with GnuTLS
Only curl 7.86.0 through 8.22.0 built with the GnuTLS backend and using WebSockets is affected. curl rates it Low despite CVSS 8.1. Fixed in 8.23.0.
- Published
- Last modified
- Where the record stands: published, rejected by its publisher, or superseded by another id.What do these mean? →
- published
- Whether CISA lists it in its Known Exploited Vulnerabilities catalog: proof that attackers are using it.What do these mean? →
- Not listed in CISA KEV
- How many real-world setups can hit the bug, from the vendor's advisory and CISA data. It does not know your setup.What do these mean? →
- Unclear
- The rating the maker of the software gives it. Shown when it differs from the CVSS level.What do these mean? →
- Low (curl)
- Fix
- Fixed in 8.14.3, 8.16.2, 8.20.2, 8.23.0
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
- Exploitation: poc
- Automatable: no
- Technical impact: total
Summary
When curl is built with GnuTLS, a malicious WebSocket server can make curl send memory past its send buffer. This is due to an out of bounds read following when `gnutls_record_send()` returns a number of bytes sent **greater than the number of bytes it was given to send**. GnuTLS does that after a blocked send.
Timeline
- CVE published
- CISA SSVC assessment
Exploitation: poc · Automatable: no · Technical impact: total
- Record last updated
Affected versions
- curl curl
From 8.22.0 · through 8.22.0; From 8.21.0 · through 8.21.0; From 8.20.0 · through 8.20.0; From 8.19.0 · through 8.19.0; From 8.18.0 · through 8.18.0; From 8.17.0 · through 8.17.0; From 8.16.0 · through 8.16.0; From 8.15.0 · through 8.15.0; From 8.14.1 · through 8.14.1; From 8.14.0 · through 8.14.0; From 8.13.0 · through 8.13.0; From 8.12.1 · through 8.12.1; From 8.12.0 · through 8.12.0; From 8.11.1 · through 8.11.1; From 8.11.0 · through 8.11.0; From 8.10.1 · through 8.10.1; From 8.10.0 · through 8.10.0; From 8.9.1 · through 8.9.1; From 8.9.0 · through 8.9.0; From 8.8.0 · through 8.8.0; From 8.7.1 · through 8.7.1; From 8.7.0 · through 8.7.0; From 8.6.0 · through 8.6.0; From 8.5.0 · through 8.5.0; From 8.4.0 · through 8.4.0; From 8.3.0 · through 8.3.0; From 8.2.1 · through 8.2.1; From 8.2.0 · through 8.2.0; From 8.1.2 · through 8.1.2; From 8.1.1 · through 8.1.1; From 8.1.0 · through 8.1.0; From 8.0.1 · through 8.0.1; From 8.0.0 · through 8.0.0; From 7.88.1 · through 7.88.1; From 7.88.0 · through 7.88.0; From 7.87.0 · through 7.87.0; From 7.86.0 · through 7.86.0
References 3
hackerone.com
Questions about CVE-2026-107928
What does this mean?
A malicious WebSocket server can make curl send data from a neighboring heap buffer in a later send call, or crash. It is triggered when a send over TLS hits EAGAIN and is followed by an automated WebSocket PONG response.Source: curl.se, curl.se
Am I affected, and how do I check?
Affected are curl 7.86.0 through 8.22.0 built with the GnuTLS TLS backend. Run curl --version to check the version and see which TLS library is listed.Source: curl.se, curl.se
What should I do about it?
Upgrade to curl 8.23.0. For the older branches, the fixed releases are 8.14.3, 8.16.2, and 8.20.2.Source: curl.se, curl.se
Is it being exploited?
It is not in CISA's Known Exploited Vulnerabilities catalog, and CISA's SSVC assessment does not mark exploitation as active. That does not mean it has not been attacked: vendors and researchers can report attacks before CISA lists them. CISA's SSVC assessment notes a proof of concept exists. No public exploit code is tracked.Source: cve.now feed data