# CVE-2026-104591: libosmocore buffer overflow in osmo_iuup_compute_payload_crc()

Source: https://junglewise.ai/threats/cve-2026-104591-libosmocore-through-1-14-1-contains-a-buffer-overflow-in-osmo  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-10-26. Updated: 2026-10-26  
License: CC BY 4.0 with a link back

CVE-2026-104591 · Severity: info · Published 2026-10-26

libosmocore is a library used in cellular network infrastructure for GSM/UMTS signal processing. A buffer overflow in IuUP payload CRC validation can be triggered by receiving network packets with payloads exceeding 1024 bytes, allowing a remote attacker to crash the service and disrupt network operations.

Technologies: [Osmocom Libosmocore](https://junglewise.ai/threats/technologies/libosmocore). Vendors: [Osmocom](https://junglewise.ai/threats/vendors/osmocom).

## Quick answers

**Is CVE-2026-104591 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-104591 being exploited in the wild.

**How severe is CVE-2026-104591?** Informational severity, published 26 October 2026.

**Which products and versions are affected?** Osmocom Libosmocore through 1.14.1.

**Is there a fix for CVE-2026-104591?** Yes: fixed in libosmocore after commit 0b0f165. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-104591 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-104591?** Check whether you run Osmocom Libosmocore at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- Fixed in libosmocore after commit 0b0f165

## Technical details

A stack buffer overflow exists in osmo_iuup_compute_payload_crc() in src/gsm/iuup.c where a fixed-size buffer is used without validating that received IuUP payloads fit within it; this occurs when osmo_pbit2ubit() is called during CRC verification. A remote attacker can send IuUP packets with payloads larger than 1024 bytes over the network to trigger a write past the stack buffer boundary, causing a denial of service.

## Affected products

- osmocom libosmocore through 1.14.1

## Timeline

- 2026-10-26: disclosed
- 2026-10-26: patched: Fix in commit 0b0f165

## References

- [https://github.com/osmocom/libosmocore/commit/0b0f165106b7918435a47f8cb28c651228b8e4aa](https://github.com/osmocom/libosmocore/commit/0b0f165106b7918435a47f8cb28c651228b8e4aa)
- [https://osmocom.org/issues/7052](https://osmocom.org/issues/7052)

## Related threats

- [libosmocore out-of-bounds read in IuUP initialization](https://junglewise.ai/threats/cve-2026-104597-libosmocore-through-1-14-1-contains-an-out-of-bounds-read-in)
- [libosmocore out-of-bounds read in GSM 04.80 parser](https://junglewise.ai/threats/cve-2026-104596-libosmocore-through-1-14-1-contains-out-of-bounds-reads-in-the)
- [libosmocore out-of-bounds read in IPA CCM identity-tag parsing](https://junglewise.ai/threats/cve-2026-104594-libosmocore-through-1-14-1-contains-out-of-bounds-reads-in-the)
- [libosmocore out-of-bounds read in CBSP decoder](https://junglewise.ai/threats/cve-2026-104592-libosmocore-through-1-14-1-contains-an-out-of-bounds-read-in-the)