VLC media player 3.0.0 through 3.0.23 Heap Out-of-Bounds Read via Unterminated RealRTSP Response Line
Summary
| CVE | CVE-2026-73324 |
|---|---|
| State | PUBLISHED |
| Assigner | VulnCheck |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-09-09 14:17:13 UTC |
| Updated | 2026-09-09 20:20:21 UTC |
| Description | VLC media player copies an RTSP response line into a fixed buffer without guaranteeing termination and then treats that buffer as a C string. RtspReadLine in modules/access/rtsp/access.c calls strncpy with the full buffer length, which writes no terminator when the source line is at least as long as the destination, and rtsp_get in modules/access/rtsp/rtsp.c allocates that buffer as BUF_SIZE bytes and passes it to strdup. When a server returns a line of 4096 bytes or more, strdup measures its length past the end of the allocation and copies adjacent heap bytes until an incidental zero byte. Because the affected line is the Session header, the disclosed bytes are retained as the session identifier and sent back to the server on every subsequent request, so the operator of a hostile server reads heap memory from the client rather than inferring it. The attacker controls the line length and therefore how far the read runs. A single playlist entry naming a realrtsp URL is sufficient. The module is a build-time option, disabled in some distribution packages and enabled in the official VideoLAN builds. |
Risk And Classification
Primary CVSS: v4.0 6.9 MEDIUM from [email protected]
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:H/VI:N/VA:N/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
EPSS: 0.003320000 probability, percentile 0.261550000 (date 2026-09-10)
Problem Types: CWE-125 | CWE-170 | CWE-125 Out-of-bounds Read | CWE-170 Improper Null Termination
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 4.0 | [email protected] | Secondary | 6.9 | MEDIUM | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/C... |
| 4.0 | CNA | CVSS | 6.9 | MEDIUM | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N |
| 3.1 | [email protected] | Primary | 6.5 | MEDIUM | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N |
| 3.1 | CNA | CVSS | 6.5 | MEDIUM | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N |
CVSS v4.0 Breakdown
Attack Vector
NetworkAttack Complexity
LowAttack Requirements
NonePrivileges Required
NoneUser Interaction
ActiveConfidentiality
HighIntegrity
NoneAvailability
NoneSub Conf.
NoneSub Integrity
NoneSub Availability
NoneCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:H/VI:N/VA:N/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
CVSS v3.1 Breakdown
Attack Vector
NetworkAttack Complexity
LowPrivileges Required
NoneUser Interaction
RequiredScope
UnchangedConfidentiality
HighIntegrity
NoneAvailability
NoneCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | VideoLAN | VLC Media Player | affected 3.0.0 3.0.23 semver | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| github.com/videolan/vlc/blob/3.0.23/modules/access/rtsp/access.c | [email protected] | github.com | |
| www.vulncheck.com/advisories/vlc-media-player-3.0.0-through-3.0.23-heap-out-of-... | [email protected] | www.vulncheck.com | |
| github.com/videolan/vlc | [email protected] | github.com | |
| github.com/videolan/vlc/blob/3.0.23/modules/access/rtsp/rtsp.c | [email protected] | github.com | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
Vendor Comments And Credit
Discovery Credit
CNA: Fabian Wahle (Hap Security) (en)
There are currently no legacy QID mappings associated with this CVE.