CVE-2026-87933: davegamble cjson
CVSS: 7.5v2.0HighDeferred
AliasesUBUNTU-CVE-2026-87933DEBIAN-CVE-2026-87933
Published 10-09-2026Last modified 10-09-2026
Vulnerability summary
CVE-2026-87933 is a high (CVSS 7.5) vulnerability in davegamble cjson. EPSS estimates a 0.53% chance of exploitation in the next 30 days, higher than 43.5% of scored vulnerabilities. 1 public exploit is recorded.
CVSS score
7.5/10
010
High · v2.0 (CVE.org)EPSS score
0.53%
0%100%
Low · +0.22 pp in 30 daysKEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits1github
Timeline
- 10-09-2026PublishedVulnerability first disclosed.
- 10-09-2026Last modifiedVulnerability information updated.
Description
A vulnerability was found in DaveGamble cJSON up to 1.7.19. The affected element is the function cJSONUtils_MergePatch of the file cJSON_Utils.c. The manipulation results in use after free. The attack may be launched remotely. The exploit has been made public and could be used. The pull request to fix this issue awaits acceptance.
CVSS metrics
10 scores · 4 sources · 4 versionsMedium 6.9Preferred score · CVE.org (CNA)
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:PSources4 sources · 5.5–6.9
- OSV · UbuntuEcosystem advisory · calculated6.9MediumCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:P
- OSV · DebianEcosystem advisory · calculated6.9MediumCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/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
- NVDNIST5.5MediumCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/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:XDiffers
High 7.3Preferred score · CVE.org (CNA)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L/E:P/RL:X/RC:RSourcesAll 3 agree
- OSV · UbuntuEcosystem advisory · calculated7.3HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L
- NVDNIST7.3HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L
High 7.3Preferred score · CVE.org (CNA)
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L/E:P/RL:X/RC:RSourcesSingle source
High 7.5Preferred score · CVE.org (CNA)
AV:N/AC:L/Au:N/C:P/I:P/A:P/E:POC/RL:ND/RC:URSourcesAll 2 agree
- NVDNIST7.5HighAV:N/AC:L/Au:N/C:P/I:P/A:P
EPSS trend
Probability
0.53%
Chance of exploitation in the next 30 days
Percentile
44%
Versus all other CVEs
30-day change
+0.22 pp
From 0.31% on 20-09-2026
20-09-202620-10-2026
EPSS score0.53%
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
1 foundCjson
Maturity: poc
Weaknesses
CWE · root cause- CWE-119Improper Restriction of Operations within the Bounds of a Memory BufferThe product performs operations on a memory buffer, but it reads from or writes to a memory location outside the buffer's intended boundary. This may result in read or write operations on unexpected memory locations that could be linked to other variables, data structures, or internal program data.
- CWE-416Use After FreeThe product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.
Affected systems
Davegamble1 product
- cjson1.7.0 | 1.7.1 | 1.7.2 | 1.7.3 | 1.7.4 | 1.7.5 | 1.7.6 | 1.7.7 | 1.7.8 | 1.7.9 | 1.7.10 | 1.7.11 | 1.7.12 | 1.7.13 | 1.7.14 | 1.7.15 | 1.7.16 | 1.7.17 | 1.7.18 | 1.7.19
Debian1 product
- cjsonAll versions (No fix recorded)
Ubuntu1 product
- cjsonAll versions (No fix recorded)
3 vendors · 3 products
References
10 links- vuldb.com/cve/CVE-2026-87933Third Party Advisory
- vuldb.com/submit/911136Third Party Advisory
- github.com/DaveGamble/cJSON/Product
