NASA cFS cFE Software Bus cfe_sb_util.c CFE_SB_GetUserDataLength integer underflow

published 2026-08-30 2 mo ago modified 2026-09-01 2 mo ago also EUVD-2026-68151

cvss: 7.4; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.4%; EPSS 0.4% chance of exploitation in 30 days, percentile 32%
public exploits: 0; none known

A security flaw has been discovered in NASA cFS up to 7.0.1. The affected element is the function CFE_SB_GetUserDataLength of the file src/cFS/cfe/modules/sb/fsw/src/cfe_sb_util.c of the component cFE Software Bus. Performing a manipulation of the argument TotalMsgSize/HdrSize results in integer underflow. It is possible to initiate the attack remotely. The vendor was contacted early about this disclosure but did not respond in any way.

CISA SSVC

Exploitation: Proof of concept is public
Automatable: no
Technical impact: partial
Assessed: 2 mo ago (2026-08-31)

Exploit prediction

0.38% chance of exploitation in the next 30 days, higher than 32% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

vuldb.com https://vuldb.com/submit/888018 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by	version	score	vector
CNA	4.0	5.3	CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:L/SC:L/SI:L/SA:L/E:X
CNA	3.1	7.4	CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:L/E:X/RL:X/RC:R
CNA	3.0	7.4	CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:L/E:X/RL:X/RC:R
CNA	2.0	6.5	AV:N/AC:L/Au:S/C:P/I:P/A:P/E:ND/RL:ND/RC:UR
CNA	4.0	5.3	CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:L/SC:L/SI:L/SA:L/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
CNA	3.1	7.4	CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:L
CNA	2.0	6.5	AV:N/AC:L/Au:S/C:P/I:P/A:P

Affected products

NASA cFS

Classification

Weakness

CWE-191 Integer Underflow (Wrap or Wraparound)
CWE-189 Numeric Errors

References

vuldb.com /submit/888018
third-party-advisory, exploit
vuldb.com /vuln/397030
vdb-entry, technical-description
vuldb.com /vuln/397030/cti
signature, permissions-required
vuldb.com /cve/CVE-2026-82480
third-party-advisory

Sources

CVE List CVE-2026-82480
NVD CVE-2026-82480

Fencer Vulns 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.

Summary