CVE-2026-103043 json
anchorme through 3.0.8 Regular Expression Denial of Service
published last mo. modified 21d ago also EUVD-2026-89484
- cvss
- 7.5
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.6%
- EPSS 0.6% chance of exploitation in 30 days, percentile 48%
- public exploits
- 0
- none known
Summary
anchorme through 3.0.8 contains a regular expression denial of service vulnerability in the IPv6 host extraction regex due to catastrophic backtracking. Attackers can supply specially crafted input strings with repeated patterns to cause exponential regex engine backtracking, blocking the Node.js event loop and denying service to other requests.
Is CVE-2026-103043 in your stack? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.
Check with FencerCISA SSVC
- Exploitation
- Proof of concept is public
- Automatable
- yes
- Technical impact
- partial
- Assessed
- last mo.
Exploit prediction
0.59% chance of exploitation in the next 30 days, higher than 48% of all scored CVEs (FIRST EPSS, 2026-11-09).
Exploits and checks
- gist.github.com https://gist.github.com/mmadersbacher/46050b4224eb979431986cdef1dd2ad3 referenced PoC, tagged "exploit" by a source, unverified
- gist.github.com https://gist.github.com/R3tro16/92948206e9893a3739b91746439384ab referenced PoC, tagged "exploit" by a source, unverified
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 4.0 | 8.7 | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N |
| CNA | 3.1 | 7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
| CNA | 4.0 | 8.7 | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X |
Affected products
- alexcorvi anchorme
Classification
- Weakness
-
- CWE-1333 Inefficient Regular Expression Complexity
References
-
gist.github.com
/mmadersbacher/46050b4224eb979431986cdef1dd2ad3
third-party-advisory, exploit
-
gist.github.com
/R3tro16/92948206e9893a3739b91746439384ab
technical-description, exploit
-
github.com
/alexcorvi/anchorme.js/blob/f3ae9850baa344f27b46bb149e9b891831d273b1/src/index.ts#L109
technical-description
-
npmjs.com
/package/anchorme
product
-
github.com
/alexcorvi/anchorme.js
product
-
vulncheck.com
/advisories/anchorme-through-3.0.8-regular-expression-denial-of-service
third-party-advisory
Sources
- CVE List CVE-2026-103043
- NVD CVE-2026-103043
Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.
CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.