predictable WebSocket mask
curl's WebSocket code did not update the 32-bit mask pattern for each new outgoing frame as the specification says. Instead it used a fixed mask that persisted and was used throughout the entire connection. A predictable mask pattern allows for a malicious server to induce traffic between the two communicating parties that could be interpreted by an involved proxy (configured or transparent) as genuine, real, HTTP traffic with content and thereby poison its cache. That cached poisoned content could then be served to all users of that proxy.
- Published
- Sep 12, 2025
- Updated
- Sep 15, 2026
- EPSS
- 0.5% · 40th percentile
- CWE
- CWE-340
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Report tools
Action score
21
Monitor
Low priority for now.
- CVSS
- 21 / 40 · 5.3 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 0 / 30 · 0.5%
CISA SSVC decision
- Exploitation
- none
- Automatable
- no
- Technical impact
- partial
Vulnrichment: CISA's decision-tree inputs.
Affected systems
| Vendor | Product | CPE |
|---|---|---|
| haxx | curl | cpe:2.3:a:haxx:curl |
Affected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- haxx curl8.11.0 and later · before 8.16.0
Versions reported by the vendor
Affected version ranges reported by the assigning authority (curl). Independent of NVD's CPE analysis and usually ahead of it.
curl curl
- 8.15.0, 8.14.1, 8.14.0, 8.13.0, 8.12.1, 8.12.0, 8.11.1, 8.11.0affected
- 8.11.0 and later · before 8.14.2affected · semver
- 8.15.0 and later · before 8.16.0affected · semver
- d78e129d50b2d190f1c1bde2ad1f62f02f152db0 and later · before 84db7a9eae8468c0445b15aa806fa7fa806fa0f2affected · git
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| Alpine:v3.19 | curl | from 8.11.0 · before 8.14.1-r2 | 8.14.1-r2 |
| Alpine:v3.23 | curl | from 8.11.0 · before 8.16.0-r0 | 8.16.0-r0 |
| Debian:12 | curl | before 7.88.1-10+deb12u15 | 7.88.1-10+deb12u15 |
| Debian:13 | curl | before 8.14.1-2+deb13u1 | 8.14.1-2+deb13u1 |
| Debian:14 | curl | before 8.16.0-1 | 8.16.0-1 |
| openSUSE:Leap 16.0 | curl | before 8.14.1-160000.3.1 | 8.14.1-160000.3.1 |
| openSUSE:Tumbleweed | curl | before 8.16.0-1.1 | 8.16.0-1.1 |
| Red Hat:hummingbird:1 | curl | before 0:8.19.0-3.hum1 | 0:8.19.0-3.hum1 |
| SUSE:Linux Enterprise High Performance Computing 15 SP3-LTSS | curl | before 8.14.1-150200.4.91.1 | 8.14.1-150200.4.91.1 |
| SUSE:Linux Enterprise High Performance Computing 15 SP3-LTSS | curl | before 8.14.1-150200.4.91.1 | 8.14.1-150200.4.91.1 |
| SUSE:Linux Enterprise Installer Updates 15 SP4 | curl | before 8.14.1-150400.5.69.1 | 8.14.1-150400.5.69.1 |
| SUSE:Linux Enterprise Micro 5.3 | brotli | before 1.0.7-150200.3.5.1 | 1.0.7-150200.3.5.1 |
| SUSE:Linux Enterprise Micro 5.3 | brotli | before 1.0.7-150200.3.5.1 | 1.0.7-150200.3.5.1 |
| SUSE:Linux Enterprise Module for Basesystem 15 SP6 | curl | before 8.14.1-150600.4.28.1 | 8.14.1-150600.4.28.1 |
| SUSE:Linux Enterprise Module for Basesystem 15 SP6 | curl | before 8.14.1-150600.4.28.1 | 8.14.1-150600.4.28.1 |
| SUSE:Linux Enterprise Server 12 SP5-LTSS | curl | before 8.0.1-11.108.1 | 8.0.1-11.108.1 |
| SUSE:Linux Enterprise Server 16.0 | curl-mini | before 8.14.1-160000.3.1 | 8.14.1-160000.3.1 |
| SUSE:Linux Micro 6.0 | curl | before 8.14.1-1.1 | 8.14.1-1.1 |
| SUSE:Linux Micro 6.1 | curl | before 8.14.1-slfo.1.1_2.1 | 8.14.1-slfo.1.1_2.1 |
| SUSE:Linux Micro 6.2 | curl | before 8.14.1-160000.3.1 | 8.14.1-160000.3.1 |
Same product
haxx: all recordsOther highest-scoring records for the same primary product.
- CVE-2021-22901curl 7.75.0 through 7.76.1 suffers from a use-after-free vulnerability resulting in already freed memory being used when a TLS 1.3 session t50Plan
- CVE-2023-38039When curl retrieves an HTTP response, it stores the incoming headers so that
they can be accessed later via the libcurl headers API.47Plan
- CVE-2024-2398HTTP/2 push headers memory-leak45Plan
- CVE-2019-5482Heap buffer overflow in the TFTP protocol handler in cURL 7.19.4 to 7.65.3.44Plan
- CVE-2017-8817The FTP wildcard function in curl and libcurl before 7.57.0 allows remote attackers to cause a denial of service (out-of-bounds read and app42Plan
- CVE-2017-8816The NTLM authentication feature in curl and libcurl before 7.57.0 on 32-bit platforms allows attackers to cause a denial of service (integer42Plan
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
| Product / package | Fixed version | Source |
|---|---|---|
| curl curl | 8.14.2 | Vendor (CNA) |
| curl curl | 8.16.0 | Vendor (CNA) |
| curl curl | 84db7a9eae8468c0445b15aa806fa7fa806fa0f2 | Vendor (CNA) |
| alpine:curl | 8.14.1-r2 · Alpine:v3.19 | Package registry (OSV) |
| debian:curl | 7.88.1-10+deb12u15 · Debian:12 | Package registry (OSV) |
| opensuse:brotli | 1.0.7-150200.3.5.1 · openSUSE:Leap 15.6 | Package registry (OSV) |
| opensuse:curl | 8.14.1-150600.4.28.1 · openSUSE:Leap 15.6 | Package registry (OSV) |
| red hat:curl | 0:8.19.0-3.hum1 · Red Hat:hummingbird:1 | Package registry (OSV) |
| suse:brotli | 1.0.7-150200.3.5.1 · SUSE:Linux Enterprise Micro 5.3 | Package registry (OSV) |
| suse:curl | 8.0.1-11.108.1 · SUSE:Linux Enterprise Server 12 SP5-LTSS | Package registry (OSV) |
| suse:curl | 8.14.1-150600.4.28.1 · SUSE:Linux Enterprise Module for Basesystem 15 SP6 | Package registry (OSV) |
| suse:curl-mini | 8.14.1-160000.3.1 · SUSE:Linux Enterprise Server 16.0 | Package registry (OSV) |
Exploit status
No known public exploit
No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.
Research context
For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.
Timeline
From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.
No dated events beyond publication.
FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).
Patch and commit links
Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.
No commit or PR link among the references.
Credits
All researchersFinders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.
- Daniel Stenbergremediation developer
- Calvin Ruocco (Vector Informatik GmbH)finder
Variant candidates
Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.
No nightly-computed relations.
Chain candidates
An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.
—
Bug bounty scope
No known public program.
Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).
Technical details
Attack conditions
- Anyone who can reach it over the internet can trigger it.
- No account or password is required.
- No user action is required.
- No special conditions are required; it is repeatable.
If successful
- Confidentiality
- low · data can be read
- Integrity
- none
- Availability
- none
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality impact
- Low
- Integrity impact
- None
- Availability impact
- None
Weakness class (CWE)
CWE-340 · Generation of Predictable Numbers or IdentifiersCVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
nvd-secondary
Attack context
MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.
MITRE has no CAPEC/ATT&CK mapping for this CWE.
Change log
- Fix✗ → ✓
For records you follow, these changes also arrive as notifications. →
References
- curl.se/docs/CVE-2025-10148.html
- curl.se/docs/CVE-2025-10148.json
- hackerone.com/reports/3330839
- www.openwall.com/lists/oss-security/2025/09/10/2
- www.openwall.com/lists/oss-security/2025/09/10/3
- www.openwall.com/lists/oss-security/2025/09/10/4
Vendor advisories and official records. Exploit/PoC links are deliberately left out.