CVE-2026-87863: HSTS response erases persisted entries
Noroxi assessment
Priority: Monitor (action score 0/100)
- The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
- Probability of exploitation in the next 30 days: 0.26% (FIRST EPSS).
- Fixed version: azl3 cmake 3.30.3-15 on Azure Linux 3.0 Release Notes; azl3 curl 8.11.1-11 on Azure Linux 3.0 Release Notes; azl3 mysql 8.0.46-2 on Azure Linux 3.0 Release Notes.
Low priority for now. Upgrade to azl3 cmake 3.30.3-15 on Azure Linux 3.0 Release Notes; azl3 curl 8.11.1-11 on Azure Linux 3.0 Release Notes; azl3 mysql 8.0.46-2 on Azure Linux 3.0 Release Notes or later.
Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it
Primary sources: NVD · CVE.org · FIRST EPSS
An authenticated HTTPS origin can supply an HSTS `max-age` value that the parser accepts, but time serialization later fails to process. On 64-bit systems, extreme max-age values compute an absolute expiry within standard time integer limits that exceeds calendar time structure bounds. During cache saves, the original HSTS file is truncated before writing a temporary replacement; when serialization fails, the temporary file is deleted, leaving an empty or partial cache. Because the save error is silently ignored during cleanup, curl exits successfully despite the data loss.
- Published
- Oct 20, 2026
- Updated
- Oct 22, 2026
- EPSS
- 0.2% · 18th percentile
- CWE
- CWE-201
Report tools
Action score
0
Monitor
Low priority for now.
- CVSS
- 0 / 40 · —
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 0 / 30 · 0.2%
Get told when this record changes
- Not in KEV: no record of exploitation in the wild
- No public exploit code on record
- A fix has been released
If any of these changes, we'll tell you in the daily email digest.
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Noroxi analysis
What does it mean in your environment?
The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.
We use this product, ask for helpAffected systems
Is your version affected?
Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.
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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
- 8.22.0 and later · up to and including 8.22.0affected · semver
- 8.21.0 and later · up to and including 8.21.0affected · semver
- 8.20.0 and later · up to and including 8.20.0affected · semver
- 8.19.0 and later · up to and including 8.19.0affected · semver
- 8.18.0 and later · up to and including 8.18.0affected · semver
- 8.17.0 and later · up to and including 8.17.0affected · semver
- 8.16.0 and later · up to and including 8.16.0affected · semver
- 8.15.0 and later · up to and including 8.15.0affected · semver
- 8.14.1 and later · up to and including 8.14.1affected · semver
- 8.14.0 and later · up to and including 8.14.0affected · semver
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| Alpine:v3.23 | curl | before 8.23.0-r0 | 8.23.0-r0 |
| Debian:13 | curl | from 0 | — |
| openSUSE:Tumbleweed | curl | before 8.23.0-1.1 | 8.23.0-1.1 |
| Red Hat:hummingbird:1 | curl | before 0:8.23.0-0.1.hum1 | 0:8.23.0-0.1.hum1 |
| Red Hat:hummingbird:1 | libcurl | before 0:8.23.0-0.1.hum1 | 0:8.23.0-0.1.hum1 |
| Red Hat:hummingbird:1 | libcurl-devel | before 0:8.23.0-0.1.hum1 | 0:8.23.0-0.1.hum1 |
| Red Hat:hummingbird:1 | libcurl-minimal | before 0:8.23.0-0.1.hum1 | 0:8.23.0-0.1.hum1 |
Same product
curl: all recordsOther highest-scoring records for the same primary product.
- CVE-2012-0036curl and libcurl 7.2x before 7.24.0 do not properly consider special characters during extraction of a pathname from a URL, which allows rem35Monitor
- CVE-2026-92392HTTP/2 upload Use-After-Free32Monitor
- CVE-2005-3185Stack-based buffer overflow in the ntlm_output function in http-ntlm.c for (1) wget 1.10, (2) curl 7.13.2, and (3) libcurl 7.13.2, and other32Monitor
Published before and after this one in the same product
- ← EarlierCVE-2026-87861Oct 20, 2026 · cross-origin reuse of a Negotiate connection0Monitor
- ← EarlierCVE-2026-87862Oct 20, 2026 · HSTS cache import drops longer-lived child0Monitor
- Later →CVE-2026-87864Oct 20, 2026 · IMAP APPEND plus CRLF conversion command injection0Monitor
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 |
|---|---|---|
| azl3 cmake 3.30.3-15 on Azure Linux 3.0 | Release Notes | Microsoft (MSRC) |
| azl3 curl 8.11.1-11 on Azure Linux 3.0 | Release Notes | Microsoft (MSRC) |
| azl3 mysql 8.0.46-2 on Azure Linux 3.0 | Release Notes | Microsoft (MSRC) |
| azl3 rust 1.75.0-31 on Azure Linux 3.0 | Release Notes | Microsoft (MSRC) |
| azl3 rust 1.96.1-2 on Azure Linux 3.0 | Release Notes | Microsoft (MSRC) |
| azl3 tensorflow 2.16.1-11 on Azure Linux 3.0 | Release Notes | Microsoft (MSRC) |
| alpine:curl | 8.23.0-r0 · Alpine:v3.23 | Package registry (OSV) |
| opensuse:curl | 8.23.0-1.1 · openSUSE:Tumbleweed | Package registry (OSV) |
| red hat:curl | 0:8.23.0-0.1.hum1 · Red Hat:hummingbird:1 | Package registry (OSV) |
| red hat:libcurl | 0:8.23.0-0.1.hum1 · Red Hat:hummingbird:1 | Package registry (OSV) |
| red hat:libcurl-devel | 0:8.23.0-0.1.hum1 · Red Hat:hummingbird:1 | Package registry (OSV) |
| red hat:libcurl-minimal | 0:8.23.0-0.1.hum1 · Red Hat:hummingbird:1 | 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.
- Published
- Fix recordedsame day
- TodayOct 28, 2026+8 d
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.
- Stanislav Fort (Aisle Research)finder
- Daniel Stenbergremediation developer
Variant candidates
Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.
- CVE-2026-864090 days apartstale SigV4 headers sent unintended0Monitor
- CVE-2026-864130 days apartNegotiate credentials sent to redirected origin0Monitor
- CVE-2026-864140 days apartleaking host credentials to HTTP proxy0Monitor
- CVE-2026-864150 days apartauto client cert connection reuse mixup0Monitor
- CVE-2026-878610 days apartcross-origin reuse of a Negotiate connection0Monitor
- CVE-2026-878620 days apartHSTS cache import drops longer-lived child0Monitor
Chain candidates
An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.
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Bug bounty scope
The product’s vendor appears in a public program. Matched by name; verify the scope text in the program.
Technical details
No CVSS vector for this record, so attack conditions can't be derived.
Weakness class (CWE)
CWE-201 · Insertion of Sensitive Information Into Sent DataAttack context
MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.
Attack patterns (CAPEC)
- Choosing Message IdentifierCAPEC-12likelihood: High · High
- Exploiting Incorrectly Configured SSL/TLSCAPEC-217likelihood: Low
- WiFi MAC Address TrackingCAPEC-612Low
- WiFi SSID TrackingCAPEC-613Low
- Cellular Broadcast Message RequestCAPEC-618Low
- Signal Strength TrackingCAPEC-619Low
- Analysis of Packet Timing and SizesCAPEC-621Low
- Electromagnetic Side-Channel AttackCAPEC-622Low
ATT&CK techniques
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Change log
- Fix✗ → ✓
- Exploit maturity— → none
For records you follow, these changes also arrive as notifications. →
References
Show all references (2 more)Show less
Vendor advisories and official records. Exploit/PoC links are deliberately left out.