CVE-2025-6494sparklemotion nokogiri hashmap.c hashmap_get_with_hash heap-based overflow
- 4.8MediumCVSS base score
- 0.18%Exploitation in 30 daysEPSS · top 92% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- YesPublic exploitsa reference or SSVC says so
Description
A vulnerability was found in sparklemotion nokogiri c29c920907366cb74af13b4dc2230e9c9e23b833. It has been classified as problematic. This affects the function hashmap_get_with_hash of the file gumbo-parser/src/hashmap.c. The manipulation leads to heap-based buffer overflow. An attack has to be approached locally. The exploit has been disclosed to the public and may be used. The real existence of this vulnerability is still doubted at the moment. The patch is named ada4708e5a67114402cd3feb70a4e1d1d7cf773a. It is recommended to apply a patch to fix this issue. The project maintainer explains that the affected code was merged into the main branch but the commit never appeared in an official release.
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
Timeline
ID reserved
By VulDB
Published
- 8 days later
· 8 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 |
|---|---|---|---|
| VulDBCNA (assigner) | 4.0 | Medium4.8 | CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:P |
| VulDBCNA (assigner) | 3.1 | Low3.3 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L/E:P/RL:O/RC:C |
| VulDBCNA (assigner) | 3.0 | Low3.3 | CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L/E:P/RL:O/RC:C |
| VulDBCNA (assigner) | 2.0 | Low1.7 | AV:L/AC:L/Au:S/C:N/I:N/A:P/E:POC/RL:OF/RC:C |
| NVDNVD · Deferred | 4.0 | Low1.9 | CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:P/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 |
- EPSS (exploitation in 30 days)
- 0.18% · top 92% of all CVEs (12 Nov 2026)
- CISA SSVC
- Exploitation: poc · Automatable: no · Technical impact: partial
The list uses the assigner's score when there is one, then CISA's, then NVD's: Medium 4.8.
Affected products
- affected c29c920907366cb74af13b4dc2230e9c9e23b833
References
References7
- VDB-313611 | sparklemotion nokogiri hashmap.c hashmap_get_with_hash heap-based overflow (opens in a new tab)vdb-entrytechnical-description
- VDB-313611 | CTI Indicators (IOB, IOC, IOA) (opens in a new tab)signaturepermissions-required
- Submit #601006 | sparklemotion nokogiri nokogiri v1.18.7 (commit a024cff) Heap-based Buffer Overflow (opens in a new tab)third-party-advisory
- https://github.com/sparklemotion/nokogiri/issues/3508 (opens in a new tab)issue-tracking
- https://github.com/sparklemotion/nokogiri/pull/3524 (opens in a new tab)issue-tracking
- https://github.com/user-attachments/files/19825279/nokogiri_crash_2.txt (opens in a new tab)exploit
- https://github.com/sparklemotion/nokogiri/commit/ada4708e5a67114402cd3feb70a4e1d1d7cf773a (opens in a new tab)patch
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-2025-18858 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (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-2025-6494)Record last updated .