8.7

CVE-2026-29036: davegamble cjson

CVSS: 8.7v4.0HighAwaiting analysis
AliasesUBUNTU-CVE-2026-29036DEBIAN-CVE-2026-29036
Published 11-08-2026Last modified 14-08-2026
Open JSON

Vulnerability summary

CVE-2026-29036 is a high (CVSS 8.7) vulnerability in davegamble cjson. EPSS estimates a 0.44% chance of exploitation in the next 30 days, higher than 37.2% of scored vulnerabilities.

Overall risk
35/100
0100
Medium · default modelHow is this calculated?
CVSS score
8.7/10
010
High · v4.0 (CVE.org)
EPSS score
0.44%
0%100%
Low · +0.19 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Timeline

  1. 11-08-2026
    PublishedVulnerability first disclosed.
  2. 14-08-2026
    Last modifiedVulnerability information updated.

Description

cJSON versions 1.5.0 through 1.7.19 contain an incorrectly-resolved name or reference vulnerability in the decode_pointer_inplace() function within cJSON_Utils.c that allows unauthenticated attackers to cause JSON Patch operations to target wrong object keys by supplying crafted JSON Pointer escape sequences (~0 or ~1) in patch paths. Attackers can submit malicious RFC 6902 JSON Patch input to applications using cJSONUtils_ApplyPatches() or cJSONUtils_ApplyPatchesCaseSensitive() to silently corrupt data or delete unintended keys, potentially bypassing authorization controls in applications that rely on JSON Patch for access-controlled data modification.

CVSS metrics

7 scores · 4 sources · 2 versions

EPSS trend

Probability

0.44%

Chance of exploitation in the next 30 days

Percentile

37%

Versus all other CVEs

30-day change

+0.19 pp

From 0.26% on 19-09-2026

19-09-202619-10-2026
EPSS score
0.44%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Davegamble1 product
  • cjson≥ 1.5.0, ≤ 1.7.19
Debian1 product
  • cjsonAll versions (No fix recorded)
Ubuntu1 product
  • cjsonAll versions (No fix recorded)

3 vendors · 3 products

References

5 links